Behavior of titanium dioxide in alumina carbothermic reduction-chlorination process in vacuum

Behaviors of TiO2 in the alumina carbothermic reduction and chlorination process in vacuum at different temperatures were investigated experimentally by means of XRD,SEM and EDS.In the preparation of materials,the molar ratio of Al2O3 to C was 1：4,and 10% TiO2 and excess AlCl3 were added.The results show that TiC is produced by C and TiO2 after TiO2 transforms from anatase into rutile gradually.In the temperature range of 1 763？1 783 K,the compounds of Ti and Al are not found in slags and condensate.The purity of aluminum reaches 98.35%,and TiO2 does not participate in alumina carbothermic reduction process and chlorination process in vacuum.

Gas-solid catalytic reactions over ruthenium-based catalysts

Ruthenium （Ru）‐based catalysts are widely employed in several types of gas‐solid reactions because of their high catalytic activities. This review provides theoretical research on Ru‐based catalysts and an analysis of their basic properties and oxidation behavior. There is particular emphasis on Ru‐catalyzed gas‐solid catalytic reactions, including the catalytic oxidation of VOCs, preferential oxidation of CO, synthesis of ammonia, oxidation of HCl and partial oxidation of CH4. Recent litera‐ture on catalysis is summarized and compared. Finally, we describe current challenges in the field and propose approaches for future development of Ru‐based catalysts.

Synthesis of C-Cl-codoped titania/attapulgite composites with enhanced visible-light photocatalytic activity

We demonstrate the synthesis of C-Cl-codoped titania/attapulgite（TiO2/ATT） composites containing a mixture of TiO2 phases by a facile sol-gel method at 70 ℃ using titanium tetraisopropoxide as the TiO2 precursor and ATT as a support for the TiO2 nanoparticles.The photocatalytic activity of the C-Cl-codoped TiO2/ATT composites with mixed anatase/brookite/rutile phases obtained at pH= 3.0 was much higher than that of commercially available Degussa P25 for the photocatalytic degradation of acid red G under visible-light irradiation.The excellent photocatalytic activity of the developed composite originates from the nonmetal codoping,which extends the absorption edge of TiO2 into visible region,and the presence of multiple phases,which slow the recombination of photoexcited electron/hole pairs.The formation of hydroxyl radicals during the photocatalytic degradation process was detected by photoluminescence probing using terephthalic acid.A mechanism for photocatalysis over the C-Cl-codoped TiO2/ATT composites was proposed.

氯气有机衍生产品(连载七)——第七章 光气及其脂肪族衍生物

第一节光气COCl2 （一）性质简介光气化学名氯甲酰氯或氧氯化碳,为无色剧毒低沸点液体。溶于甲苯、二甲苯、氯苯、醋酸、二氯乙烷、煤油中;微溶于苯、氯仿、四氯化碳中;溶于水微分解生成二氧化碳和氯化氢。不可燃,密度（0℃）1.427克/厘米3,熔点—127.8℃,沸点7.48℃。与胺类反应生成相应酮 COCl2+2RNH2→RNHCONHR……用于染料中间体之制造。

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

AIM： To investigate the effects of Nigella sativa 1 （NS） and Urtica dioica 1 （UD） on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS： Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups： A （CCl4-only treated）, B （CCl4＋UD treated）, C （CCl4＋NS treated） and D （CCl4＋UD＋NS treated）, each containing 14 animals. All groups received CCl4 （0.8 mL/kg of body weight, sc, twice a week for 60 d）. In addition, B, C and D groups also received daily i.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand, received only 2 mL/kg normal saline solution for 60 d. Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment. RESULTS： The CCl4 treatment for 60 d increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatment （alone or combination） for 60 d decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. The weight of rats decreased in group A, and increased in groups B, C and D. CONCLUSION： NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defense system activity in the CCl4-treated rats.

Protective effects of medical ozone combined with traditional Chinese medicine against chemically-induced hepatic injury in dogs

AIM： To investigate the protective effect of medical ozone （O3） combined with Traditional Chinese Medicine （TCM） Yigan Fuzheng Paidu Capsules （YC） against carbon tetrachloride （CCh）-induced hepatic injury in dogs. METHODS： Thirty healthy dogs were divided randomly into five groups （n = 6 in each group）, namely control, oleanolic acid tablet （OAT）, O3, YC and O3 ＋ YC, given either no particular pre-treatment, oral OAT, medical ozone rectal insulfflation every other day, oral YC, or oral YC plus medical ozone rectal insulfflation every other day, respectively, for 30 consecutive days. After pre-treatment, acute hepatic injury was induced in all dogs with a single-dose intraperitoneal injection of CCh. General condition and survival time were recorded. The biochemical and hematological indexes of alanine aminotransferase （ALT）, aspartate aminotransferase/ alanine aminotransferase （AST/ALT）, serum total bUirubin （TBIL）, prothrombin time （PT）, blood ammonia （AMMO）, and blood urea nitrogen （BUN） were measured after CCh injection. Hepatic pathological changes were also observed.RESULTS： Compared to the other four groups, the changes of group O3 ＋ YC dogs＇ general conditions （motoricity, mental state, eating, urination and defecation） could be better controlled. In group O3 ＋ YC the survival rates were higher （P 〈 0.05 vs group control）. AST/ALT values were kept within a normal level in group O3 ＋ YC. Hepatic histopathology showed that hepatic injury in group O3 ＋ YC was less serious than those in the other four groups.CONCLUSION： Medical ozone combined with TCM YC could exert a protective effect on acute liver injury induced by CCI4,

Effect of Oxymatrine on the TGFbeta-Smad signaling pathway in rats with CCl_4-induced hepatic fibrosis

AIM： To explore the anti-fibrotic effect of Oxymatrine on CCl4-induced liver fibrosis in rats and its modulation on the TGFbeta-Smad signaling pathway. METHODS： One hundred healthy male SD rats were randomly divided into three groups： normal group （n = 20）, treatment group of Oxymatrine （n = 40） and CCh-induced fibrosis group （n = 40）. Experimental hepatic fibrosis was induced by subcutaneous injection of carbon tetrachloride （CCh soluted in liquid paraffin with the concentration of 300 g/L, the dosage of injection was 3 mL/kg, twice per week for 8 wk）. The treated rats received Oxymatrine via celiac injection at a dosage of 10 mg/kg twice a week at the same time. The deposition of collagen was observed with H＆E and Masson staining. The concentration of serum TGF-β1 was assayed with ELISA. The gene expression of Smads and CBP （CREB binding protein） was detected with in situ hybridization （ISH） and immunohistochemistry （IH）, respectively. All the experimental figures were scanned and analyzed with special figure-analysis software. RESULTS： A significant reduction of collagen deposition and rearrangement of the parenchyma was noted in the liver tissue of Oxymatrine-treated rats. The semi- quantitative histological scores （2.43 ± 0.47 μm^2 vs 3.76 ±0.68, P 〈 0.05） and average area of collagen/in those rats were significantly decreased when compared with hepatic cirrhosis model rats （94.41 ± 37.26 μm^2 vs 290.86 ± 89.37 μm^2, P 〈 0.05）. The gene expression of Smad 3 mRNA was considerably decreased in the treated animals. The A value of Smad 3 mRNA was lower in the treated rats than the model rats （0.034 ± 0.090 vs 0.167 ± 0.092, P 〈 0.05）. Contrarily, the A value of Smad 7 mRNA was increased considerably in the treated animals （0.175 ± 0.065 vs 0.074 vs 0.012, P 〈 0.05）. There was an obvious decrease in the expression of CBP mRNA in treated rats as illuminated by a reduction of its A value when compared with model rats （0.065±0.049 vs 0.235 ± 0.025, P 〈 0.001）. CONCLUSION： Oxymatrine is effective in reducing the production and deposition of collagen in the liver tissue of experimental rats. Oxymatrine could promote the expression of Smad 7 and inhibit the expression of Smad 3 and CBP in CCh-induced hepatic fibrosis in SD rats, could modulate the fibrogenic signal transduction of TGFβ-Smad pathway.

Progress in the Study on the Phase Equilibria of the CO2·H2O and CO2-HeO-NaCI Systems

To study the feasibility of CO2 geological sequestration,it is needed to understand the complicated mul- tiple-phase equilibrium and the densities of aqueous solution with CO2 and multi-ions under wide geological condi- tions(273.15—473.15K,0—60MPa),which are also essential for designing separation equipments in chemical or oil-related industries.For this purpose,studies on the relevant phase equilibria and densities are reviewed and ana- lyzed and the method to improve or modify the existing model is suggested in order to obtain more reliable pre- dictions in a wide temperature and pressure range.Besides,three different models(the electrolyte non random two-liquid(ELECNRTL),the electrolyte NRTL combining with Helgeson model(ENRTL-HG),Pitzer activity co- efficient model combining with Helgeson model(PITZ-HG))are used to calculate the vapor-liquid phase equilib- rium of CO2-H2O and CO2-H2O-NaCl systems.For CO2-H2O system,the calculation results agree with the experi- mental data very well at low and medium pressure(0—20MPa),but there are great discrepancies above 20MPa.For the water content at 473.15K,the calculated results agree with the experimental data quite well.For the CO2-H2O-NaCl system,the PITZ-HG model show better results than ELECNRTL and ENRTL-HG models at the NaCl concentration of 0.52mol·L -1 .Bur for the NaCl concentration of 3.997mol·L -1 ,using the ELECNRTL and ENRTL-HG models gives better results than using the PITZ-HG model.It is shown that available experimental data and the thermodynamic calculations can satisfy the needs of the calculation of the sequestration capacity in the temperature and pressure range for disposal of CO2 in deep saline aquifers.More experimental data and more accu- rate thermodynamic calculations are needed in high temperature and pressure ranges(above 398.15K and 31.5MPa).

Oxygen and nitrogen-doped metal-free carbon catalysts for hydrochlorination of acetylene

Activated carbon was tested as metal-free catalyst for hydrochlorination of acetylene in order to circumvent the problem of environment pollution caused by mercury and high cost by noble metals. Oxygen-doped and nitrogen-doped activated carbons were prepared and characterized by XPS, TPD and N2 physisorption methods. The influences of the surface functional groups on the catalytic performance were discussed base on these results. Among all the samples tested, a nitrogen-doped sample, AC-n-US00, exhibited the best performance, the acety- lene conversion being 92% and vinyl chloride selectivity above 99% at 240 ~C and C2H2 hourly space velocity 30 h- 1. Moreover, the AC-n-US00 catalyst exhibited a stable performance during a 200 h test with a conversion of acetylene higher than 76% at 210 ~C at a C2H2 hourly space velocity 50 h 1. In contrary, oxygen-doped catalyst had lower catalytic activities. A linear relationship between the amount of pyrrolic-N and quaternary-N species and the catalytic activity was observed, indicating that these nitrogen-doped species might be the active sites and the key in tuning the catalytic performance. It is also found that the introduction of nitrogen species into the sample could significantly increase the adsorption amount of acetylene. The deactivation of nitrogen- doped activated carbon might be caused by the decrease of the accessibility to or the total amount of active sites.

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

AIM： To evaluate the hepatoprotective roles of （Z）- 5-（4-methoxybenzylidene）thiazolidine-2,4-dione （SKLB010） against carbon tetrachloride （CCI4）-induced acute and chronic liver injury and its underlying mecha- nisms of action.

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

AIM： To evaluate the protective effect of 2′-p-hydroxy benzoylmussaenosidic acid [negundoside （NG）, against carbon tetrachloride （CCl4）-induced toxicity in HUH-7 cel Is.METHODS： CCI4 is a well characterized hepatotoxin, and inducer of cytochrome P450 2E1 （CYP2E1）-mediated oxidative stress. In addition, lipid peroxidation and accumulation of intracellular calcium are important steps in the pathway involved in CCl4 toxicity. Liver cells （HUH-7） were treated with CCI4, and the mechanism of the cytoprotective effect of NG was assessed. Silymarin, a known hepatoprotective drug, was used as control. RESULTS： NG protected HUH-7 cells against CCl4 toxicity and loss of viability without modulating CYP2E1 activity. Prevention of CCl4 toxicity was associated with a reduction in oxidative damage as reflected by decreased generation of reactive oxygen species （ROS）, a decrease in lipid peroxidation and accumulation of intracellular Ca^2＋ levels and maintenance of intracellular glutathione homeostasis. Decreased mitochondrial membrane potential （MMP）, induction of caspases mediated DNA fragmentation and cell cycle arrest, as a result of CCl4 treatment, were also blocked by NG. The protection afforded by NG seemed to be mediated by activation of cyclic adenosine monophosphate （cAMP） synthesis and inhibition of phospholipases （cPLA2）. CONCLUSION： NG exerts a protective effect on CYP2E1-dependent CCl4 toxicity via inhibition of lipid peroxidation, followed by an improved intracellular calcium homeostasis and inhibition of Ca^2＋-dependent proteases.

ZnCl2 salt facilitated preparation of FeNC: Enhancing the content of active species and their exposure for highly-efficient oxygen reduction reaction

Introducing catalytically-active Fe and N into carbon materials results in promising FeNC catalysts for oxygen reduction reaction. However, the doped Fe and N species are frequently subject to heavy loss in a traditional carbonization process owing to Fe agglomeration and evaporation of N-contained small molecules. Besides, pyrolysis may make materials sintering which embeds a large number of active sites in the bulk phase and impedes direct exposure of reactive centers to the reactants. We here report that when calcinations, the addition of ZnCl2, an ordinary salt with very wide melting temperature range well covering the carbonization process of the precursor iron porphyrin, can significantly enhance the doping level of the active species and simultaneously create highly porous structures for FeNC catalysts. The obtained FeNC demonstrates ultrahigh catalytic activities even significantly better than Pt/C in oxygen reduction reaction.

Carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacolborate catalyzed by palladium nanoparticles

Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacol-borate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfactory to good yields. The carboxylative Suzuki coupling reaction proceeded smooth-ly under mild conditions in the presence of palladium nanoparticles generated in situ through the formation of a π-benzylpalladium chloride intermediate.

Efficient Solvent-free Synthesis of Chloropropene Carbonate from the Coupling Reaction of CO_2 and Epichlorohydrin Catalyzed by Magnesium Porphyrins as Chlorophyll-like Catalysts

Highly efficient solvent-free coupling reaction of carbon dioxide(CO2)and epichlorohydrin catalyzed by meso-tetraphenyl porphyrin magnesium(MgTPP)in the presence of triethylamine as co-catalysts is reported.As a chlorophyll-like catalyst,MgTPP showed excellent activity for the coupling reaction of CO2 and epichlorohydrin to chloropropene carbonate,in which the turnover number could reach up to 9200.Moreover,different factors including the amount of catalyst,reaction temperature,pressure and time were systematically investigated and the optimal reaction conditions were obtained(epichlorohydrin 50 mmol,MgTPP 5.0×10- 3mmol,triethylamine 6.25×10-3 mmol,140°C,1.5 MPa,8 h).A plausible two-pathway mechanism for the coupling reaction of CO 2and epichlorohydrin is proposed to propound the catalysis of MgTPP.

Carbon Dioxide Control-Technology for the Future

The world is experiencing global climate change, and most scientists attribute it to the accumulation in the atmosphere of carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons. Because of its enormous emission rate, carbon dioxide （CO2） is the main culprit. Almost all the anthropogenic CO2 emissions come from the burning of fossil fuels for electricity, heat, and transportation. Emissions of COg can be reduced by conservation, increased use of renewable energy sources, and increased efficiencies in both the production of electrical power and the transportation sector. Capture of CO2 can be accomplished with wet scrubbing, dry sorption, or biogenic fixation. After CO2 is captured, it must be transported either as a liquid or a supercritical fluid, which realistically can only be accomplished by pipeline or ship. Final disposal of CO2 will either be to underground reservoirs or to the ocean; at present, the underground option seems to be the only viable one. Various strategies and technologies involved with reduction of CO2 emissions and carbon capture and sequestration （CCS） are briefly reviewed in this paper.

Adsorption and Transfer Properties for Toluene and pDichlorobenzene in Dense CO_2/Silica Gel Packed Bed System by Moment Method and Time-Domain Analysis

Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficient and effective intra-particle diffusivity) for toluene and p-dichlorobenzene on silica gel adsorbent in the subcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and the experiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methods have been compared. The results show that for the systems studied here the moment method can give reasonable values for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only can obtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transfer properties on temperature and pressure was investigated.

Hepatoprotective and antioxidant effects of baicalin against CCl4-induced hepatotoxicity

Scutellaria baicalensis is widely cultivated in eastern Asia, particularly in China. In the present study, we isolated baicalin from this plant and studied for its hepatoprotective activity against CCl4-induced oxidative damage in rats. Our findings revealed that baicalin exhibited strong antioxidant activity in vitro. In established in vivo tests, baicalin showed effective protective effects by reducing the elevated levels of glutamate pyruvate transaminase （ALT）, aspartate aminotransferase （AST）, alkaline phosphatase （ALP）, total bilirubin （TB） and malondialdehyde （MDA） against CCl4-induced damage, and it restored the activities antioxidant defense substances, such as superoxide dismutase （SOD）, catalase （CAT） and glutathione （GSH）, toward their normal levels. These data were supplemented with histopathological examination of rat liver sections. The results demonstrated that baicalin could be proposed to protect the liver against CCh-induced oxidative damage in rats, and the possible underlying mechanism of the activity could be due to its free radical-scavenging and antioxidant activity.

The alleviating effect of quercetin on carbon tetrachloride-induced liver fibrosis in rats and its underlying mechanism

Quercetin, a phenolic phytochemical widely present in vegetables and fruits, has antioxidant, anti-inflammatory, antiviral, and immunomodulatory activities, and it has been successfully used in the treatment of acute and chronic diseases. In the present study, we aimed to investigate the alleviation effect of quercetin on rat liver fibrosis and explore its mechanism of action. Healthy male SD rats were randomly divided into the normal group, model group, and quercetin group, with six rats in each group. Liver fibrosis was induced by intraperitoneal injection of 1 m L/kg carbon tetrachloride(50% v/v in olive oil) twice a week for 6 weeks, and quercetin(100 mg/kg/d) was administered orally in the 7th week until the end of the 12th week. Blood and liver samples were collected at 1 h after the last administration. Serum liver function parameters(AST, ALT, ALP, GGT, and TBA) were detected by an automatic biochemical analyzer. H&E, Masson, and Sirius red staining were used to observe the pathological morphology of liver tissue. Western blotting analysis was used to evaluate the expressions of liver fibrotic factors(TGF-β1, α-SMA, MMP2, and MMP9) and bile acid-related regulatory proteins(FXR, CYP7A1, CYP8B1, and CYP27A1). The oxidative stress markers(GSH, GSH-Px, GR, SOD, and MDA) in the liver tissue were detected using corresponding kits. The contents of bile acids in the liver tissue were determined by LC-MS/MS. The results showed that compared with the model group, quercetin treatment could significantly reduce serum AST, ALT, and TBA levels(P < 0.05). The fibrotic liver injury was significantly improved, and the expressions of fibrotic factors TGF-β1, α-SMA, MMP2, and MMP9 were significantly decreased(P < 0.05). Liver GSH, GSH-Px, GR, and SOD levels were significantly increased(P < 0.05), and the MDA level was significantly decreased(P < 0.05). The contents of hepatic bile acids were significantly decreased(P < 0.05), the expression of FXR was significantly increased(P < 0.05), and the expressions of CYP7A1 and CYP8B1 were significantly decreased(P < 0.05). This study suggested that quercetin could effectively alleviate carbon tetrachloride-induced liver fibrosis injury, and its mechanism of action was related to improving the liver’s ability to resist oxidative stress and reducing the expressions of fibrotic factors and bile acid synthesis.