To extract molybdenum and nickel from the roasted Ni-Mo ore, a process of hydrochloric acid leaching, sulphation roasting and water leaching was investigated. The results showed that this process could get a high leac...To extract molybdenum and nickel from the roasted Ni-Mo ore, a process of hydrochloric acid leaching, sulphation roasting and water leaching was investigated. The results showed that this process could get a high leaching rate of Mo and Ni. Under the optimum conditions of hydrochloric acid leaching （roasted Ni-Mo ore leached with 0.219 mL/g hydrochloric acid addition at 65 ℃ for 30 min with a L/S ratio of 3 mL/g）, sulphation roasting （51.9% sulfiaric acid addition, roasting temperature 240 ℃ for 1 h）, followed by leaching with the first stage hydrochloric acid leaching solution at 95 ℃ for 2 h, the leaching rates of Mo and Ni reached 95.8% and 91.3%, respectively.展开更多
Cyanobacterial blooms or algae problems in aquaculture fish-ponds are becoming a big concern to fish farmers due to reduced production of fish.Although several studies have been conducted around the globe focusing on ...Cyanobacterial blooms or algae problems in aquaculture fish-ponds are becoming a big concern to fish farmers due to reduced production of fish.Although several studies have been conducted around the globe focusing on cyanobacterial blooms in oceans and lakes,little has been done on inhibition of algal biomass impacting fish-ponds in aquaculture industry.The present study assessed the potential of banana peel ashes and potassium sulphate on algal growth inhibition within fish-ponds based on a six-weeks mesocosm experiment conducted with varying ash concentrations(i.e.,2,4,6,8,10 g·L-1).This study analysed differences among treatments for the various nutrient variables(nitrates,ammonium and phosphates)at the end of the experiment.The significant experimental differences in physicochemical variables among the study weeks(i.e.,1–6 weeks),treatments(three levels,including controls)and ash concentrations using factorial repeated measures ANOVA were further tested.Moreover,algal growth was determined in order to test the efficiency of treatment n inhibiting algal growth by measuring chlorophyll-a concentration across 6 weeks.Banana peel ashes performed significantly well on inhibition of algal growth than potassium sulphate,except for controls.However,no clear patterns between pH and conductivity were observed throughout the experiment.The present study found that banana peel ashes do not have notable effects on water quality variable,particularly physicochemical parameters,which did not significantly change from first week of experiment.With banana peel ashes being the best inhibitor according to the findings of the present study,further studies are required to investigate the effects of banana peel ashes on fish within the ponds.展开更多
Microbiologically driven acidic pollution of coal gangue has become amajor environmental problem in coal gangue dumps in coal mining areas.Addition of bactericides and sulphate reducing bacteria(SRB)is an effective me...Microbiologically driven acidic pollution of coal gangue has become amajor environmental problem in coal gangue dumps in coal mining areas.Addition of bactericides and sulphate reducing bacteria(SRB)is an effective means to control the acidic pollution of coal gangue,but their mechanism of action has not been fully investigated.By adding bactericide,SRB and bactericide-SRB to the newly produced coal gangue,respectively,the effects of these treatments on the microbial community structure were observed.Changes in pH and electrical conductivity(EC)of the gangue leaching solution,as well as themicrobial community composition and functional abundance on the gangue surface were analysed by leaching simulation experiments and 16S rRNA sequencing.The results showed that(1)the addition of bactericide-SRB was the most effective treatment to elevate pH before 8 d,while the addition of SRB performed best after 22 d(2)The addition of bactericide and SRB drastically changed the microbial community structure on the gangue surface.Simultaneous addition of both had the best inhibitory effect on pathogenic bacteria and Thiobacillus.(3)All three treatments promote higher abundance of genes related to nitrogen cycling,but reflected in different gene functions.Microorganisms with sulfate respiration function in the experimental group all showed different increases.The abundance of other sulfur cycle genes decreased substantially.However,Human Pathogens All had higher abundance than control check(CK)in each treatment,whichmay indicate that the addition of either bactericides or SRB increases the risk of microbial pathogenicity to humans.展开更多
This research examines the impact of sulphate on pore water pressure(PWP)development in cement paste backfill(CPB)containing polycarboxylate ether(PES)superplasticizers under thermal-hydraulic-mechanical-chemical(THMC...This research examines the impact of sulphate on pore water pressure(PWP)development in cement paste backfill(CPB)containing polycarboxylate ether(PES)superplasticizers under thermal-hydraulic-mechanical-chemical(THMC)conditions that imitate actual field curing scenarios.PWP in CPB-PES,with and without sulphate,was assessed under non-isothermal field curing temperatures,varied drainage conditions,and curing stresses using a specially experimental setup.Key findings indicate that PWP behavior in CPB with PES under field conditions diverges markedly from standard laboratory conditions due to the significant effects of field curing temperatures,drainage conditions,and backfill self-weight.The study establishes that high sulphate ion concentrations notably increase initial PWP and slow its dissipation by interfering with the cement hydration process.This interference delays hydration,reduces pore water consumption,and lowers capillary pressure.Moreover,the results show that THMC conditions,especially non-isothermal field temperatures and varied drainage scenarios,considerably accelerate cement hydration compared to standard laboratory conditions,resulting in a more rapid decrease in PWP.Furthermore,improved drainage under THMC conditions mitigates the adverse effects of sulphates by facilitating sulphate ion removal,thus supporting more efficient cement hydration and CPB self-desiccation.The insights gained from this research are essential for understanding PWP behavior in sulphate-bearing CPB-PES in the field,developing predictive THMC models for backfill performance assessment,and enhancing the safety and effectiveness of mining backfills.展开更多
This study was carried out to evaluate the response of Nile tilapia(Oreochromis niloticus)fingerlings to acute copper sulphate and ferrocene toxicity.Nile tilapia fingerlings weighing 2.3±0.2 g were acclimated an...This study was carried out to evaluate the response of Nile tilapia(Oreochromis niloticus)fingerlings to acute copper sulphate and ferrocene toxicity.Nile tilapia fingerlings weighing 2.3±0.2 g were acclimated and randomly distributed at a rate of 10 fish per 30 L aquarium.Fish were exposed to a range of copper sulphate and ferrocene concentrations of 4 mg/L,8 mg/L,12 mg/L,16 mg/L and 2.5 mg/L,5 mg/L,7.5 mg/L,10 mg/L respectively.Fish not exposed to any toxicant served as control.Mortality was assessed and median lethal concentration(LC50)and median lethal time(LT50)were calculated.The 96-h LC50 values obtained for copper sulphate and ferrocene were 7.49 mg/L(confidence interval CI:6.35 to 8.57 mg/L)and 3.55 mg/L(CI:0.98 to 5.17 mg/L)respectively.The LC50 decreased with time of exposure implying that toxicity increased over time,however,LT50 decreased as concentration increased.The safe concentration for copper sulphate derived was 1.913 mg/L and 1.196 mg/L for ferrocene.Histological analyses were carried out on fish gills and skin.The skin histomorphology showed marked and widespread epidermal loss and widespread mycocytic degeneration in treatments with high concentration for both toxicants.The gill morphology showed moderate to severe hyperplasia of the primary gill epithelia leading to partial or complete loss of the secondary lamellae.展开更多
The mitigation of sulphation and parasitic hydrogen evolution is considered as prominent research emphasis for the development of lead-carbon batteries(LCBs)in large-scale energy storage applications.Here,cooperative ...The mitigation of sulphation and parasitic hydrogen evolution is considered as prominent research emphasis for the development of lead-carbon batteries(LCBs)in large-scale energy storage applications.Here,cooperative Pb-C composites consisting of single atom Pb and carbon-encapsulated PbO nanoparticles were prepared by freeze-drying technique and pyrolytic reduction to address above obstacles.The innovative use of Pb^(2+)to cross-link sodium alginate enabled a uniform distribution of Pb in the composites,generating Pb-C-PbO three-phase heterostructure.Experimental analysis and theoretical calculations revealed the synergistic interactions between single-atom Pb and PbO nanoparticles in suppressing parasitic hydrogen evolution and promoting the adsorption of Pb atoms.The presence of monatomic Pb and PbO enhanced the affinity of the composites for the negative active materials and facilitated the transformation of the active materials from bulk into spherical shapes to enhance the specific surface area,thereby counteracting sulphation.Through the coordinated integration of various functionalities offered by Pb@C-x,the cycle life of the battery at HRPSoC reaches 7025 cycles,which is two times for LCB with pure carbon materials.Additionally,the discharge capacity increased from 3.52 to 3.79 Ah.This study provides substantial insights into the construction of Pb-C composites for LCBs to inhibit negative sulphation and hydrogen evolution.展开更多
The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorp...The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorption tower of the AC flue gas purification system were carried out to first calibrate the thermal desorption characteristics of adsorbed NH_(3) and sulphate and explore the reaction behaviour of NH_(3) with SO_(2) and H_(2)SO_(4). On this basis, some advice for optimising the sulphate generation was put forward to improve the purification efficiency of the AC system. The results show that the temperatures of the desorption of adsorbed NH_(3), the decomposition of (NH_(4))_(2)SO_(4) and NH_(4)HSO_(4) are 224, 276 and 319 ℃, respectively, which lays the foundation for the quantitative analysis of sulphate on AC. Regardless of the NH_(3) amount, only a small portion of H_(2)SO_(4) is converted to sulphate, as the H_(2)SO_(4) deposited in AC pores or agglomerated together could not come into contact with NH_(3). The final reaction product of NH_(3) and SO_(2) is mainly (NH_(4))_(2)SO_(4) which is continuously generated because the newly generated H_(2)SO_(4) is continually exposed to NH_(3), if NH_(3) is enough. The reaction of NH_(3) with H_(2)SO_(4) takes precedence over with NH_(4)HSO_(4). In the initial stages in which H_(2)SO_(4) is exposed to NH_(3), the product is essentially all NH_(4)HSO_(4) as intermediate. Then, it is further converted to (NH_(4))_(2)SO_(4) whose amount reaches equilibrium when the accessible H_(2)SO_(4) is exhausted. All the NH_(3) adsorbed on AC entering the desulphurisation tower generates NH_(4)HSO_(4), but the amount is limited. The remaining SO_(2) entering the denitrification tower mainly generates (NH_(4))_(2)SO_(4);thus, limiting the remaining SO_(2) amount is necessary to guarantee denitrification efficiency. When the NH_(3) injection is changed to the desulphurisation tower, the initial NH_(3) injection rate can be increased to complete the conversion of accessible H_(2)SO_(4) as soon as possible in order to obtain higher denitrification efficiency.展开更多
Over recent decades, Gampaha district, Sri Lanka, has experienced significant urbanisation and industrial growth, increasing groundwater demand due to limited and polluted surface water resources. In 2013, a community...Over recent decades, Gampaha district, Sri Lanka, has experienced significant urbanisation and industrial growth, increasing groundwater demand due to limited and polluted surface water resources. In 2013, a community uprising in Rathupaswala, a village in Gampaha district, accused a latex glove manufacturing factory of causing groundwater acidity (pH < 4). This study evaluates the spatial and temporal changes in geochemical parameters across three transects in the southern part of Gampaha district to 1) assess the impact of geological formations on groundwater;2) compare temporal variations in groundwater;and 3) explain acidification via a geochemical model. Seventy-two sample locations were tested for pH, electrical conductivity (EC), and anion concentrations (sulphate, nitrate, chloride and fluoride). Depth to the water table and distance from the sea were measured to study variations across sandy, peaty, lateritic, and crystalline aquifers. Results showed pH readings around 7 for sandy and crystalline aquifers, below 7 for peaty aquifers, and below 5 for lateritic aquifers, with significant water table fluctuations near Rathupaswala area. Principal component analysis revealed three principal components (PCs) explaining 86.0% of the variance. PC1 (40.6%) correlated with pH, EC, and sulphate (saltwater intrusion), while PC2 (32.0%) correlated with nitrates and depth to the water table (anthropogenic nutrient pollution). A geochemical transport model indicated a cone of depression recharged by acidic groundwater from peat-soil aquifers, leading to acidic groundwater in Rathupaswala area. Previous attributions of acidic pH to the over-exploitation of groundwater by the latex factory have been reevaluated;the results suggest natural acidification from prolonged water-rock interactions with iron-rich lateritic aquifers. Groundwater pH is influenced by local climate, geology, topography, and drainage systems. It is recommended that similar water-rock interaction conditions may be present throughout the wet zone of Sri Lanka, warranting detailed studies to confirm this hypothesis.展开更多
Colistin sulfate is an antibiotic in the polymyxin family that is utilized as a last-resort therapy for septicemia in humans caused by multidrugresistant infections.However,its indiscriminate use in veterinary practic...Colistin sulfate is an antibiotic in the polymyxin family that is utilized as a last-resort therapy for septicemia in humans caused by multidrugresistant infections.However,its indiscriminate use in veterinary practices poses an increasingly significant risk to the development of colistin resistance and its detrimental effects on public health.Colistin is still widely used in animals for treatment,metaphylaxis,prophylaxis,and growth promotion despite being designated a critically important antimicrobial for human medicine by the World Health Organization(WHO)[1].In this correspondence,our objective is to examine the repercussions stemming from the illicit use of colistin in livestock and poultry in Nepal.展开更多
In this study,the bacteria from the mud in tidal-flat Sinonovacula constricta aquaculture area were isolated each month from March to December,2002,and the temporal and spatial distribution of heterotrophic bacteria,a...In this study,the bacteria from the mud in tidal-flat Sinonovacula constricta aquaculture area were isolated each month from March to December,2002,and the temporal and spatial distribution of heterotrophic bacteria,ammonifying bacteria,denitrifying bacteria,and sulphate reducing bacteria were analyzed.The results showed that all the 515 isolated bacteria mainly belonged to 1 family and 13 genera.The bacterial flora in different layers of the mud was almost consistent,while the composition was different.The predominant genera were Clostridium,Bacillus,Corynebacterium,Photobacterium,and some Enterobacteriaceae.The number of heterotrophic bacteria in the surface layer and the bottom fluctuated in 7.6×103 cfu·g-1～2.0×105 and 1.6×103～1.0×105 cfu·g-1,ammonifying bacteria fluctuated in 1.5×106～9.0×107 and 9.0×105～1.0×107 cfu·g-1,denitrifying bacteria fluctuated in 9.0×103～4.0×106 and 5.0×102～1.9×106 cfu·g-1,and sulphate reducing bacteria fluctuated in 5.0×104～5.0×106 and 1.9×104～2.0×106 cfu·g-1,respectively.The detection rates of ammonifying bacteria,denitrifying bacteria and sulphate reducing bacteria in the mud were all 100%,and these bacteria increased significantly in the second half of the year,indicating that the environment of the Sinonovacula constricta aquaculture area was deteriorated due to the accumulation of NH3,nitrite and H2S,and it is important to regulate the breed capacity and redistribute the breeding environment.展开更多
Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal rea...Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal reaction parameters are proposed as follows： n（CaO）/n（Fe2＋） 1.4：1, reaction temperature 80 ℃, ferrous ion concentration 0.4 mol/L, and the final mole ratio of Fe3＋ to FJ＋ in the reaction solution 1.9-2.1. In magnetic separation process, the effects of milling time and magnetic induction intensity on iron recovery were investigated. Wet milling played an important part in breaking the encapsulated magnetic phases. The results showed that the mixed product was wet-milled for 20 min before magnetic separation, the grade and recovery rate of iron in magnetite concentrate were increased from 51.41% and 84.15% to 62.05% and 85.35%, respectively.展开更多
The effect of MnO4- and silver content on electrochemical behaviour of five commercial Pb-Ag alloy anodes was studied in acid zinc sulphate electrolyte with and without MnO4- ions at 38 °C during potential decay ...The effect of MnO4- and silver content on electrochemical behaviour of five commercial Pb-Ag alloy anodes was studied in acid zinc sulphate electrolyte with and without MnO4- ions at 38 °C during potential decay periods. When the anodes were immersed into acid zinc sulphate electrolyte without MnO4- ions, the Pb-0.72%Ag anode entered complete passivation state in the shortest time among the five anodes, followed by anodes Pb-0.67%Ag, Pb-0.60%Ag, Pb-0.58%Ag and Pb-0.29%Ag-0.1%Ca by measurement of open circuit potential. During immersion of the anodes, MnO4 ions accelerated the passivation and increased the corrosion current density of the anodes. After immersion in zinc electrolyte with MnO4-, the anode Pb-0.72%Ag had the best corrosion resistance, followed by anodes Pb-0.67%Ag, Pb-0.60%Ag, then the close anodes Pb-0.58%Ag and Pb-0.29%Ag-0.1%Ca by the electrochemical impedance spectroscopy （EIS） analysis.展开更多
In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological charact...In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.展开更多
[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different f...[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.展开更多
The corrosion behaviours of die-cast AZ91D magnesium alloys were investigated in 0.1 mol/L sodium sulphate （Na 2 SO 4 ） solutions with different pH values. The corrosion rates, morphologies, and compositions of the ...The corrosion behaviours of die-cast AZ91D magnesium alloys were investigated in 0.1 mol/L sodium sulphate （Na 2 SO 4 ） solutions with different pH values. The corrosion rates, morphologies, and compositions of the corrosion products were studied by means of scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR）, and X-ray diffractometry （XRD）. The results indicate that the order of corrosion rates in Na 2 SO 4 solutions with various pH values is pH 2pH 4pH 7pH 9pH 12. The corrosion rates in acidic solutions are higher than those in alkaline solutions, and the corrosion products are mainly magnesium hydroxide （Mg（OH） 2 ） and hydrated sulphate pickeringite （MgAl 2 （SO 4 ） 4 ·22H 2 O）. The results also indicate that the solution pH can influence the corrosion rate and morphology of corrosion products. Chloride ions and sulphate ions have different pitting initiation time.展开更多
The pharmacokinetics of morphine sulphate was studied in 10 Chinese healthy volunteers after a single oral dose. Blood samples were collected before and after administration of controlled release tablets (CRMS, 30 mg)...The pharmacokinetics of morphine sulphate was studied in 10 Chinese healthy volunteers after a single oral dose. Blood samples were collected before and after administration of controlled release tablets (CRMS, 30 mg) and immediate release tablets (IRMS, 20 mg). The plasma concentration of morphine was determined by GC MS. The pharmacokinetic parameters of controlled release tablets and immediate release tablets were calculated∶ C max was 19.38±3.80 and 21.27±6.21 ng/ml, t max was 2.36 ±0.37 h and 0.56±0.16 h, t 1/2β was 3.53±0.87 and 3.03±0.74 h, AUC was 145.15±17.65 and 93.08±16.65 ng/ml, respectively. The steady state plasma concentration of morphine sulphate in cancer patients after multiple doses was achieved, C max of CRMS and IRMS was 27.43±0.33 ng/ml and 22.68±0.16 ng/ml, C min of CRMS and IRMS was 19.45±1.44 ng/ml and 18.14±0.49 ng/ml, respectively.展开更多
AIM:To investigate the therapeutic effect of Schistosoma mansoni(S.mansoni) soluble worm proteins on gastrointestinal motility disturbances during experimental colitis in mice. METHODS:Colitis was induced by intrarect...AIM:To investigate the therapeutic effect of Schistosoma mansoni(S.mansoni) soluble worm proteins on gastrointestinal motility disturbances during experimental colitis in mice. METHODS:Colitis was induced by intrarectal injection of trinitrobenzene sulphate(TNBS) and 6 h later,mice were treated ip with S.mansoni proteins.Experiments were performed 5 d after TNBS injection.Inflammationwas quantified using validated inflammation parameters. Gastric emptying and geometric center were measured to assess in vivo gastrointestinal motility.Peristaltic activity of distal colonic segments was studied in vitro using a modified Trendelenburg set-up.Cytokine profiles of T-lymphocytes isolated from the colon were determined by real time reverse transcriptase-polymerase chain reaction. RESULTS:Intracolonic injection of TNBS caused severe colitis.Treatment with S.mansoni proteins significantly ameliorated colonic inflammation after 5 d.TNBS did not affect gastric emptying but significantly decreased the geometric center and impaired colonic peristaltic activity 5 d after the induction of colitis.Treatment with S.mansoni proteins ameliorated these in vivo and in vitro motility disturbances.In addition,TNBS injection caused a downregulation of effector T cell cytokines after 5 d,whereas a S.mansoni protein effect was no longer observed at this time point. CONCLUSION:Treatment with S.mansoni proteins attenuated intestinal inflammation and ameliorated motility disturbances during murine experimental colitis.展开更多
AIM: To study whether matrix metalloproteinase-9 (MMP-9) is a key factor in epithelial damage in the dextran sodium sulphate (DSS) model of colitis in mice.METHODS: MMP-9-deficient and wild-type (wt) mice were given 5...AIM: To study whether matrix metalloproteinase-9 (MMP-9) is a key factor in epithelial damage in the dextran sodium sulphate (DSS) model of colitis in mice.METHODS: MMP-9-deficient and wild-type (wt) mice were given 5% DSS in drinking water for 5 d followed by recovery up to 7 d. On d 5 and 12 after induction of colitis, gelatinases, MMP-2 and MMP-9, were measured in homogenates of colonic tissue by zymography and Western blot, whereas tissue inhibitor of metalloproteinases (TIMPs) were measured by reverse zymography. The gelatinolytic activity was also determined in supernatants of polymorphonuclear leukocytes (PMN) isolated from mice blood. Moreover, intestinal epithelial cells were stimulated with TNF-α to study whether these cells were able to produce MMPs. Finally, colonic mucosal lesions were measured by microscopic examination. RESULTS: On d 5 of colitis, the activity of MMP-9 was increased in homogenates of colonic tissues (0.24 ± 0.1 vs 21.3 ± 6.4, P < 0.05) and PMN from peripheral blood in wt (0.5 ± 0.1 vs 10.4 ± 0.7, P < 0.05), but not in MMP-9-deficient animals. The MMP-9 activity was also up-regulated by TNF-α in epithelial intestinal cells (2.5 ± 0.5 vs 14.7 ± 3.0, P < 0.05). Although colitis also led to increase of TIMP-1 activity, the MMP-9/TIMP-1 balance remained elevated. Finally, in the MMP-9-deficient colitic mice both the extent and severity of intestinal epithelialinjury were significantly attenuated when compared with wt mice. CONCLUSION: We conclude that DSS induced colitis is markedly attenuated in animals lacking MMP-9. This suggests that intestinal injury induced by DSS is modu-lated by MMP-9 and that inhibition of this gelatinase may reduce inflammation.展开更多
Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridiza...Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population.Sulfate-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.展开更多
Valuable metal extraction technology from thermal power plant fly ash is limited.In the present study,aluminium is extracted from fly ash as highly pure aluminium sulphate(>99.0%)by leaching with sulphuric acid,fol...Valuable metal extraction technology from thermal power plant fly ash is limited.In the present study,aluminium is extracted from fly ash as highly pure aluminium sulphate(>99.0%)by leaching with sulphuric acid,followed by pre-concentration and successive crystallization.Two types of fly ashes from different sources,i.e.,Talcher Thermal Power Station(TTPS)and Vedanta Aluminium Company Limited(VAL)were chosen for comparative study on the extraction of aluminium as aluminium sulphate.The product is characterized by powder X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric analysis(TGA).Purity of aluminium sulphate was also investigated by inductively coupled plasma?optical emission spectrometry(ICP?OES).The extraction efficiency of aluminium depends on the varied solid-to-liquid ratio(fly ash:18mol/L H2SO4,g/mL)and particle size of fly ashes.Physico-chemical analysis indicates that the obtained product is Al2(SO4)3·18H2O,having low iron content(0.08%).展开更多
基金Project(51104186)supported by the National Natural Science Foundation of ChinaProjects(2016zzts282,2016zzts283)supported by the Fundamental Research Funds for the Central Universities of Central South University,China
文摘To extract molybdenum and nickel from the roasted Ni-Mo ore, a process of hydrochloric acid leaching, sulphation roasting and water leaching was investigated. The results showed that this process could get a high leaching rate of Mo and Ni. Under the optimum conditions of hydrochloric acid leaching （roasted Ni-Mo ore leached with 0.219 mL/g hydrochloric acid addition at 65 ℃ for 30 min with a L/S ratio of 3 mL/g）, sulphation roasting （51.9% sulfiaric acid addition, roasting temperature 240 ℃ for 1 h）, followed by leaching with the first stage hydrochloric acid leaching solution at 95 ℃ for 2 h, the leaching rates of Mo and Ni reached 95.8% and 91.3%, respectively.
基金supported by National Research Foundation Masters Scholarship(UID:106618).
文摘Cyanobacterial blooms or algae problems in aquaculture fish-ponds are becoming a big concern to fish farmers due to reduced production of fish.Although several studies have been conducted around the globe focusing on cyanobacterial blooms in oceans and lakes,little has been done on inhibition of algal biomass impacting fish-ponds in aquaculture industry.The present study assessed the potential of banana peel ashes and potassium sulphate on algal growth inhibition within fish-ponds based on a six-weeks mesocosm experiment conducted with varying ash concentrations(i.e.,2,4,6,8,10 g·L-1).This study analysed differences among treatments for the various nutrient variables(nitrates,ammonium and phosphates)at the end of the experiment.The significant experimental differences in physicochemical variables among the study weeks(i.e.,1–6 weeks),treatments(three levels,including controls)and ash concentrations using factorial repeated measures ANOVA were further tested.Moreover,algal growth was determined in order to test the efficiency of treatment n inhibiting algal growth by measuring chlorophyll-a concentration across 6 weeks.Banana peel ashes performed significantly well on inhibition of algal growth than potassium sulphate,except for controls.However,no clear patterns between pH and conductivity were observed throughout the experiment.The present study found that banana peel ashes do not have notable effects on water quality variable,particularly physicochemical parameters,which did not significantly change from first week of experiment.With banana peel ashes being the best inhibitor according to the findings of the present study,further studies are required to investigate the effects of banana peel ashes on fish within the ponds.
文摘Microbiologically driven acidic pollution of coal gangue has become amajor environmental problem in coal gangue dumps in coal mining areas.Addition of bactericides and sulphate reducing bacteria(SRB)is an effective means to control the acidic pollution of coal gangue,but their mechanism of action has not been fully investigated.By adding bactericide,SRB and bactericide-SRB to the newly produced coal gangue,respectively,the effects of these treatments on the microbial community structure were observed.Changes in pH and electrical conductivity(EC)of the gangue leaching solution,as well as themicrobial community composition and functional abundance on the gangue surface were analysed by leaching simulation experiments and 16S rRNA sequencing.The results showed that(1)the addition of bactericide-SRB was the most effective treatment to elevate pH before 8 d,while the addition of SRB performed best after 22 d(2)The addition of bactericide and SRB drastically changed the microbial community structure on the gangue surface.Simultaneous addition of both had the best inhibitory effect on pathogenic bacteria and Thiobacillus.(3)All three treatments promote higher abundance of genes related to nitrogen cycling,but reflected in different gene functions.Microorganisms with sulfate respiration function in the experimental group all showed different increases.The abundance of other sulfur cycle genes decreased substantially.However,Human Pathogens All had higher abundance than control check(CK)in each treatment,whichmay indicate that the addition of either bactericides or SRB increases the risk of microbial pathogenicity to humans.
文摘This research examines the impact of sulphate on pore water pressure(PWP)development in cement paste backfill(CPB)containing polycarboxylate ether(PES)superplasticizers under thermal-hydraulic-mechanical-chemical(THMC)conditions that imitate actual field curing scenarios.PWP in CPB-PES,with and without sulphate,was assessed under non-isothermal field curing temperatures,varied drainage conditions,and curing stresses using a specially experimental setup.Key findings indicate that PWP behavior in CPB with PES under field conditions diverges markedly from standard laboratory conditions due to the significant effects of field curing temperatures,drainage conditions,and backfill self-weight.The study establishes that high sulphate ion concentrations notably increase initial PWP and slow its dissipation by interfering with the cement hydration process.This interference delays hydration,reduces pore water consumption,and lowers capillary pressure.Moreover,the results show that THMC conditions,especially non-isothermal field temperatures and varied drainage scenarios,considerably accelerate cement hydration compared to standard laboratory conditions,resulting in a more rapid decrease in PWP.Furthermore,improved drainage under THMC conditions mitigates the adverse effects of sulphates by facilitating sulphate ion removal,thus supporting more efficient cement hydration and CPB self-desiccation.The insights gained from this research are essential for understanding PWP behavior in sulphate-bearing CPB-PES in the field,developing predictive THMC models for backfill performance assessment,and enhancing the safety and effectiveness of mining backfills.
文摘This study was carried out to evaluate the response of Nile tilapia(Oreochromis niloticus)fingerlings to acute copper sulphate and ferrocene toxicity.Nile tilapia fingerlings weighing 2.3±0.2 g were acclimated and randomly distributed at a rate of 10 fish per 30 L aquarium.Fish were exposed to a range of copper sulphate and ferrocene concentrations of 4 mg/L,8 mg/L,12 mg/L,16 mg/L and 2.5 mg/L,5 mg/L,7.5 mg/L,10 mg/L respectively.Fish not exposed to any toxicant served as control.Mortality was assessed and median lethal concentration(LC50)and median lethal time(LT50)were calculated.The 96-h LC50 values obtained for copper sulphate and ferrocene were 7.49 mg/L(confidence interval CI:6.35 to 8.57 mg/L)and 3.55 mg/L(CI:0.98 to 5.17 mg/L)respectively.The LC50 decreased with time of exposure implying that toxicity increased over time,however,LT50 decreased as concentration increased.The safe concentration for copper sulphate derived was 1.913 mg/L and 1.196 mg/L for ferrocene.Histological analyses were carried out on fish gills and skin.The skin histomorphology showed marked and widespread epidermal loss and widespread mycocytic degeneration in treatments with high concentration for both toxicants.The gill morphology showed moderate to severe hyperplasia of the primary gill epithelia leading to partial or complete loss of the secondary lamellae.
基金supported by the National Natural Science Foundation of China (52064028,22002054)Yunnan Fundamental Research Projects (202401AT070334,202101AS070013)Yunnan Provincial Major Science and Technology Special Plan Projects (202202AF080002)。
文摘The mitigation of sulphation and parasitic hydrogen evolution is considered as prominent research emphasis for the development of lead-carbon batteries(LCBs)in large-scale energy storage applications.Here,cooperative Pb-C composites consisting of single atom Pb and carbon-encapsulated PbO nanoparticles were prepared by freeze-drying technique and pyrolytic reduction to address above obstacles.The innovative use of Pb^(2+)to cross-link sodium alginate enabled a uniform distribution of Pb in the composites,generating Pb-C-PbO three-phase heterostructure.Experimental analysis and theoretical calculations revealed the synergistic interactions between single-atom Pb and PbO nanoparticles in suppressing parasitic hydrogen evolution and promoting the adsorption of Pb atoms.The presence of monatomic Pb and PbO enhanced the affinity of the composites for the negative active materials and facilitated the transformation of the active materials from bulk into spherical shapes to enhance the specific surface area,thereby counteracting sulphation.Through the coordinated integration of various functionalities offered by Pb@C-x,the cycle life of the battery at HRPSoC reaches 7025 cycles,which is two times for LCB with pure carbon materials.Additionally,the discharge capacity increased from 3.52 to 3.79 Ah.This study provides substantial insights into the construction of Pb-C composites for LCBs to inhibit negative sulphation and hydrogen evolution.
基金support of China Petrochemical Corporation Funding(Sinopec Group,No.321094).
文摘The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorption tower of the AC flue gas purification system were carried out to first calibrate the thermal desorption characteristics of adsorbed NH_(3) and sulphate and explore the reaction behaviour of NH_(3) with SO_(2) and H_(2)SO_(4). On this basis, some advice for optimising the sulphate generation was put forward to improve the purification efficiency of the AC system. The results show that the temperatures of the desorption of adsorbed NH_(3), the decomposition of (NH_(4))_(2)SO_(4) and NH_(4)HSO_(4) are 224, 276 and 319 ℃, respectively, which lays the foundation for the quantitative analysis of sulphate on AC. Regardless of the NH_(3) amount, only a small portion of H_(2)SO_(4) is converted to sulphate, as the H_(2)SO_(4) deposited in AC pores or agglomerated together could not come into contact with NH_(3). The final reaction product of NH_(3) and SO_(2) is mainly (NH_(4))_(2)SO_(4) which is continuously generated because the newly generated H_(2)SO_(4) is continually exposed to NH_(3), if NH_(3) is enough. The reaction of NH_(3) with H_(2)SO_(4) takes precedence over with NH_(4)HSO_(4). In the initial stages in which H_(2)SO_(4) is exposed to NH_(3), the product is essentially all NH_(4)HSO_(4) as intermediate. Then, it is further converted to (NH_(4))_(2)SO_(4) whose amount reaches equilibrium when the accessible H_(2)SO_(4) is exhausted. All the NH_(3) adsorbed on AC entering the desulphurisation tower generates NH_(4)HSO_(4), but the amount is limited. The remaining SO_(2) entering the denitrification tower mainly generates (NH_(4))_(2)SO_(4);thus, limiting the remaining SO_(2) amount is necessary to guarantee denitrification efficiency. When the NH_(3) injection is changed to the desulphurisation tower, the initial NH_(3) injection rate can be increased to complete the conversion of accessible H_(2)SO_(4) as soon as possible in order to obtain higher denitrification efficiency.
文摘Over recent decades, Gampaha district, Sri Lanka, has experienced significant urbanisation and industrial growth, increasing groundwater demand due to limited and polluted surface water resources. In 2013, a community uprising in Rathupaswala, a village in Gampaha district, accused a latex glove manufacturing factory of causing groundwater acidity (pH < 4). This study evaluates the spatial and temporal changes in geochemical parameters across three transects in the southern part of Gampaha district to 1) assess the impact of geological formations on groundwater;2) compare temporal variations in groundwater;and 3) explain acidification via a geochemical model. Seventy-two sample locations were tested for pH, electrical conductivity (EC), and anion concentrations (sulphate, nitrate, chloride and fluoride). Depth to the water table and distance from the sea were measured to study variations across sandy, peaty, lateritic, and crystalline aquifers. Results showed pH readings around 7 for sandy and crystalline aquifers, below 7 for peaty aquifers, and below 5 for lateritic aquifers, with significant water table fluctuations near Rathupaswala area. Principal component analysis revealed three principal components (PCs) explaining 86.0% of the variance. PC1 (40.6%) correlated with pH, EC, and sulphate (saltwater intrusion), while PC2 (32.0%) correlated with nitrates and depth to the water table (anthropogenic nutrient pollution). A geochemical transport model indicated a cone of depression recharged by acidic groundwater from peat-soil aquifers, leading to acidic groundwater in Rathupaswala area. Previous attributions of acidic pH to the over-exploitation of groundwater by the latex factory have been reevaluated;the results suggest natural acidification from prolonged water-rock interactions with iron-rich lateritic aquifers. Groundwater pH is influenced by local climate, geology, topography, and drainage systems. It is recommended that similar water-rock interaction conditions may be present throughout the wet zone of Sri Lanka, warranting detailed studies to confirm this hypothesis.
文摘Colistin sulfate is an antibiotic in the polymyxin family that is utilized as a last-resort therapy for septicemia in humans caused by multidrugresistant infections.However,its indiscriminate use in veterinary practices poses an increasingly significant risk to the development of colistin resistance and its detrimental effects on public health.Colistin is still widely used in animals for treatment,metaphylaxis,prophylaxis,and growth promotion despite being designated a critically important antimicrobial for human medicine by the World Health Organization(WHO)[1].In this correspondence,our objective is to examine the repercussions stemming from the illicit use of colistin in livestock and poultry in Nepal.
文摘In this study,the bacteria from the mud in tidal-flat Sinonovacula constricta aquaculture area were isolated each month from March to December,2002,and the temporal and spatial distribution of heterotrophic bacteria,ammonifying bacteria,denitrifying bacteria,and sulphate reducing bacteria were analyzed.The results showed that all the 515 isolated bacteria mainly belonged to 1 family and 13 genera.The bacterial flora in different layers of the mud was almost consistent,while the composition was different.The predominant genera were Clostridium,Bacillus,Corynebacterium,Photobacterium,and some Enterobacteriaceae.The number of heterotrophic bacteria in the surface layer and the bottom fluctuated in 7.6×103 cfu·g-1～2.0×105 and 1.6×103～1.0×105 cfu·g-1,ammonifying bacteria fluctuated in 1.5×106～9.0×107 and 9.0×105～1.0×107 cfu·g-1,denitrifying bacteria fluctuated in 9.0×103～4.0×106 and 5.0×102～1.9×106 cfu·g-1,and sulphate reducing bacteria fluctuated in 5.0×104～5.0×106 and 1.9×104～2.0×106 cfu·g-1,respectively.The detection rates of ammonifying bacteria,denitrifying bacteria and sulphate reducing bacteria in the mud were all 100%,and these bacteria increased significantly in the second half of the year,indicating that the environment of the Sinonovacula constricta aquaculture area was deteriorated due to the accumulation of NH3,nitrite and H2S,and it is important to regulate the breed capacity and redistribute the breeding environment.
基金Project(2013A090100013)supported by the Special Project on the Integration of Industry,Education and Research of Guangdong Province,ChinaProject(201407300993)supported by the High Technology Research and Development Program of Xinjiang Uygur Autonomous Region,China
文摘Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal reaction parameters are proposed as follows： n（CaO）/n（Fe2＋） 1.4：1, reaction temperature 80 ℃, ferrous ion concentration 0.4 mol/L, and the final mole ratio of Fe3＋ to FJ＋ in the reaction solution 1.9-2.1. In magnetic separation process, the effects of milling time and magnetic induction intensity on iron recovery were investigated. Wet milling played an important part in breaking the encapsulated magnetic phases. The results showed that the mixed product was wet-milled for 20 min before magnetic separation, the grade and recovery rate of iron in magnetite concentrate were increased from 51.41% and 84.15% to 62.05% and 85.35%, respectively.
基金Project(RDCPJ346365-06)supported by the Natural Sciences and Engineering Research Council of CanadaProject(51208193)supported by the National Natural Science Foundation of ChinaProject(11jj6034)supported by the Hunan Provincial Natural Science Foundation
文摘The effect of MnO4- and silver content on electrochemical behaviour of five commercial Pb-Ag alloy anodes was studied in acid zinc sulphate electrolyte with and without MnO4- ions at 38 °C during potential decay periods. When the anodes were immersed into acid zinc sulphate electrolyte without MnO4- ions, the Pb-0.72%Ag anode entered complete passivation state in the shortest time among the five anodes, followed by anodes Pb-0.67%Ag, Pb-0.60%Ag, Pb-0.58%Ag and Pb-0.29%Ag-0.1%Ca by measurement of open circuit potential. During immersion of the anodes, MnO4 ions accelerated the passivation and increased the corrosion current density of the anodes. After immersion in zinc electrolyte with MnO4-, the anode Pb-0.72%Ag had the best corrosion resistance, followed by anodes Pb-0.67%Ag, Pb-0.60%Ag, then the close anodes Pb-0.58%Ag and Pb-0.29%Ag-0.1%Ca by the electrochemical impedance spectroscopy （EIS） analysis.
文摘In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.
基金Supported by Construction Project of Maize Industry Technology System of Modern Agriculture in Yunnan Province(Yunnong(ke)2009-53Yunnongcai(2009-171))~~
文摘[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.
基金Project(51044007)supported by the National Natural Science Foundation of ChinaProject(08121018)supported by the Science and Technology Project of Taiyuan City,China+2 种基金Project(20091402110010)supported by the Doctoral Found of Ministry of Education of ChinaProject(2008029)supported by the Shanxi Province Foundation for Returned Scholars,ChinaProject(20093007)supported by the Young Subject-Leader Foundation and the Innovative Project for Outstanding Post-graduate of Shanxi Province,China
文摘The corrosion behaviours of die-cast AZ91D magnesium alloys were investigated in 0.1 mol/L sodium sulphate （Na 2 SO 4 ） solutions with different pH values. The corrosion rates, morphologies, and compositions of the corrosion products were studied by means of scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR）, and X-ray diffractometry （XRD）. The results indicate that the order of corrosion rates in Na 2 SO 4 solutions with various pH values is pH 2pH 4pH 7pH 9pH 12. The corrosion rates in acidic solutions are higher than those in alkaline solutions, and the corrosion products are mainly magnesium hydroxide （Mg（OH） 2 ） and hydrated sulphate pickeringite （MgAl 2 （SO 4 ） 4 ·22H 2 O）. The results also indicate that the solution pH can influence the corrosion rate and morphology of corrosion products. Chloride ions and sulphate ions have different pitting initiation time.
文摘The pharmacokinetics of morphine sulphate was studied in 10 Chinese healthy volunteers after a single oral dose. Blood samples were collected before and after administration of controlled release tablets (CRMS, 30 mg) and immediate release tablets (IRMS, 20 mg). The plasma concentration of morphine was determined by GC MS. The pharmacokinetic parameters of controlled release tablets and immediate release tablets were calculated∶ C max was 19.38±3.80 and 21.27±6.21 ng/ml, t max was 2.36 ±0.37 h and 0.56±0.16 h, t 1/2β was 3.53±0.87 and 3.03±0.74 h, AUC was 145.15±17.65 and 93.08±16.65 ng/ml, respectively. The steady state plasma concentration of morphine sulphate in cancer patients after multiple doses was achieved, C max of CRMS and IRMS was 27.43±0.33 ng/ml and 22.68±0.16 ng/ml, C min of CRMS and IRMS was 19.45±1.44 ng/ml and 18.14±0.49 ng/ml, respectively.
基金Supported by The Fund of Scientific Research(FWO),Flanders, Project G.0134.07the University of Antwerp,BOF Grant FA02/3/3257
文摘AIM:To investigate the therapeutic effect of Schistosoma mansoni(S.mansoni) soluble worm proteins on gastrointestinal motility disturbances during experimental colitis in mice. METHODS:Colitis was induced by intrarectal injection of trinitrobenzene sulphate(TNBS) and 6 h later,mice were treated ip with S.mansoni proteins.Experiments were performed 5 d after TNBS injection.Inflammationwas quantified using validated inflammation parameters. Gastric emptying and geometric center were measured to assess in vivo gastrointestinal motility.Peristaltic activity of distal colonic segments was studied in vitro using a modified Trendelenburg set-up.Cytokine profiles of T-lymphocytes isolated from the colon were determined by real time reverse transcriptase-polymerase chain reaction. RESULTS:Intracolonic injection of TNBS caused severe colitis.Treatment with S.mansoni proteins significantly ameliorated colonic inflammation after 5 d.TNBS did not affect gastric emptying but significantly decreased the geometric center and impaired colonic peristaltic activity 5 d after the induction of colitis.Treatment with S.mansoni proteins ameliorated these in vivo and in vitro motility disturbances.In addition,TNBS injection caused a downregulation of effector T cell cytokines after 5 d,whereas a S.mansoni protein effect was no longer observed at this time point. CONCLUSION:Treatment with S.mansoni proteins attenuated intestinal inflammation and ameliorated motility disturbances during murine experimental colitis.
基金Supported by Instituto de Salud Carlos Ⅲ (C03/02), FEDER funds, Fundación Canaria de Investigación (PI 21/02), and Spanish Ministry of Education to CM (EX2004-0396)
文摘AIM: To study whether matrix metalloproteinase-9 (MMP-9) is a key factor in epithelial damage in the dextran sodium sulphate (DSS) model of colitis in mice.METHODS: MMP-9-deficient and wild-type (wt) mice were given 5% DSS in drinking water for 5 d followed by recovery up to 7 d. On d 5 and 12 after induction of colitis, gelatinases, MMP-2 and MMP-9, were measured in homogenates of colonic tissue by zymography and Western blot, whereas tissue inhibitor of metalloproteinases (TIMPs) were measured by reverse zymography. The gelatinolytic activity was also determined in supernatants of polymorphonuclear leukocytes (PMN) isolated from mice blood. Moreover, intestinal epithelial cells were stimulated with TNF-α to study whether these cells were able to produce MMPs. Finally, colonic mucosal lesions were measured by microscopic examination. RESULTS: On d 5 of colitis, the activity of MMP-9 was increased in homogenates of colonic tissues (0.24 ± 0.1 vs 21.3 ± 6.4, P < 0.05) and PMN from peripheral blood in wt (0.5 ± 0.1 vs 10.4 ± 0.7, P < 0.05), but not in MMP-9-deficient animals. The MMP-9 activity was also up-regulated by TNF-α in epithelial intestinal cells (2.5 ± 0.5 vs 14.7 ± 3.0, P < 0.05). Although colitis also led to increase of TIMP-1 activity, the MMP-9/TIMP-1 balance remained elevated. Finally, in the MMP-9-deficient colitic mice both the extent and severity of intestinal epithelialinjury were significantly attenuated when compared with wt mice. CONCLUSION: We conclude that DSS induced colitis is markedly attenuated in animals lacking MMP-9. This suggests that intestinal injury induced by DSS is modu-lated by MMP-9 and that inhibition of this gelatinase may reduce inflammation.
基金financially supported by the National Natural Science Foundation of China (Nos.51478456 and 51178451)
文摘Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population.Sulfate-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.
基金Funding from CSIR, New Delhi, under network project (ESC.205)
文摘Valuable metal extraction technology from thermal power plant fly ash is limited.In the present study,aluminium is extracted from fly ash as highly pure aluminium sulphate(>99.0%)by leaching with sulphuric acid,followed by pre-concentration and successive crystallization.Two types of fly ashes from different sources,i.e.,Talcher Thermal Power Station(TTPS)and Vedanta Aluminium Company Limited(VAL)were chosen for comparative study on the extraction of aluminium as aluminium sulphate.The product is characterized by powder X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric analysis(TGA).Purity of aluminium sulphate was also investigated by inductively coupled plasma?optical emission spectrometry(ICP?OES).The extraction efficiency of aluminium depends on the varied solid-to-liquid ratio(fly ash:18mol/L H2SO4,g/mL)and particle size of fly ashes.Physico-chemical analysis indicates that the obtained product is Al2(SO4)3·18H2O,having low iron content(0.08%).
