Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole(1)and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4]triazolo[4,3-b][1,2,4]triazole(9)were synthesized through the convenient cyclization reaction f...Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole(1)and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4]triazolo[4,3-b][1,2,4]triazole(9)were synthesized through the convenient cyclization reaction from the readily available reactant.Their energetic salts with high nitrogen content were proved to be rare examples of divalent monocyclic/fused cyclic cationic salts according to the single crystal analyses.The structure of intermediate B was also identified and verified by its trivalent cation crystal 17.5H_2O indirectly.Energetic compounds 2-8 and 10-17 were fully characterized by NMR spectroscopy,infrared spectroscopy,differential scanning calorimetry,elemental analysis.These energetic salts exhibit good thermal stability with decomposition temperatures ranged from 182℃to 245℃.The sensitivity of compounds 2,6,10 and 14 is similar or superior to that of RDX while the others were much more insensitive to mechanical stimulate.Furthermore,detonation velocity of 10(8843 m/s)surpass that of RDX(D=8795 m/s).Considering the high gas production volume(≥808 L/kg)of 2,4,10and 12,constant-volume combustion experiments were conduct to evaluate their gas production capacities specifically.These compounds possess much higher maximum gas-production pressures(P_(max):7.88-10.08 MPa)than the commonly used reagent guanidine nitrate(GN:P_(max)=4.20 MPa),which indicate their strong gas production capacity.展开更多
The mixed lineage kinase domain-like(MLKL)protein is a key factor in tumor necrosis factor-induced necroptosis.Recent studies on necroptosis execution revealed a commitment role of MLKL in membrane disruption.However,...The mixed lineage kinase domain-like(MLKL)protein is a key factor in tumor necrosis factor-induced necroptosis.Recent studies on necroptosis execution revealed a commitment role of MLKL in membrane disruption.However,our knowledge of how MLKL functions on membrane remains very limited.Here we demonstrate that MLKL forms cation channels that are permeable preferential y to Mg2+rather than Ca2+in the presence of Na+and K+.Moreover,the N-terminal domain containing six helices(H1-H6)is sufficient to form channels.Using the substituted cysteine accessibility method,we further determine that helix H1,H2,H3,H5 and H6 are transmembrane segments,while H4 is located in the cytoplasm.Finally,MLKL-induced membrane depolarization and cell death exhibit a positive correlation to its channel activity.The Mg2+-preferred permeability and five transmembrane segment topology distinguish MLKL from previously identified Mg2+-permeable channels and thus establish MLKL as a novel class of cation channels.展开更多
As a strategy for phytopathogen control throughtransgenic way,antimicrobial peptide genes havebeen employed over the last two decades.CEMA is a cationic antimicrobial chimericpeptide,which is produced by fusing eighta...As a strategy for phytopathogen control throughtransgenic way,antimicrobial peptide genes havebeen employed over the last two decades.CEMA is a cationic antimicrobial chimericpeptide,which is produced by fusing eightamino acid residues from the antimicrobialpeptide ceropin A with a modified meltin.Threetransgenic cotton plants were generated展开更多
The most remarkable effect in spinel ferrites is the strong dependence of properties on the state of structural disorder and,in particular,on the cation distribution.The structural characterization of a Co-Zn ferrite ...The most remarkable effect in spinel ferrites is the strong dependence of properties on the state of structural disorder and,in particular,on the cation distribution.The structural characterization of a Co-Zn ferrite nanoparticle sample was reported which prepared by wet chemical co-precipitation method.The samples were sintered at three different temperatures viz.650℃,850℃ and 1050℃ for 12 h.The structural details like:lattice constant and distribution of cations in the tetrahedral and octahedral interstitial voids have been deduced through X-ray diffraction (XRD) data analysis.Lattice constant was found to increase with the increase in Zn2+ ions and sintering temperature.Theoretical intensity ratios of (220),(400),(440) planes were considered,as these reflections are sensitive to cations on the A and B sites.Close agreement of the theoretical intensity ratio with the intensity ratio observed from XRD pattern supports the occupancy of Zn2+ ions and Co2+ ions on the octahedral and tetrahedral sites,respectively.展开更多
OBJECTIVE To investigate how MLKL functions on the membrane and explore its electrophysiological characters and structure.METHODS The full-length human MLKL were expressed in SF21 cells and purified using glutathione-...OBJECTIVE To investigate how MLKL functions on the membrane and explore its electrophysiological characters and structure.METHODS The full-length human MLKL were expressed in SF21 cells and purified using glutathione-sepharose affinity chromatography.The currents of purified MLKL proteins were recorded in avoltage-clamp mode using a Warner BC-535 bilayer clamp amplifier.The currents were digitized using p CLAMP 10.2 software.HEK293 cells were cultured and transfected with MLKL plasmid.Cell viability was examined using the Cell Titer-Glo Luminescent Cell Viability Assay kit.RESULT MLKL forms cation channels that are permeable preferentially to Mg2+rather than Ca2+in the presence of Na+and K+.Moreover,each MLKL monomer contains five transmembrane helices:H1,H2,H3,H5 and H6 of the N-terminal domain which is sufficient to form channels.Finally,MLKL-induced membrane depolarization and cell death exhibit a positive correlation to its channel activity.展开更多
Zinc extraction from crude zinc oxide(CZO)is beneficial to the full utilization of secondary resources and environmental protection.In this paper,a systematic investigation was carried out to study the leaching behavi...Zinc extraction from crude zinc oxide(CZO)is beneficial to the full utilization of secondary resources and environmental protection.In this paper,a systematic investigation was carried out to study the leaching behavior of CZO by using ammonia-ammonium carbonate solution.It was found that the maximum leaching rate of zinc from CZO dust was 95.7%under the conditions of[Zn]T:[NH 3]T:[CO_(3)^(2−)]=1:7.00:1.75,liquid to solid ratio 5:1,leaching temperature 30℃ and leaching time 60 min.Compared with pure zinc oxide(PZO)leaching,the CZO leaching required longer time and more leaching agents,which is caused by the Cd^(2+),Pb^(2+) and other metal cationic impurities in CZO.The metal cationic impurities dissolved in the leaching solution and combined with ammonium to form complexes,consuming leaching agents and affecting zinc leaching.展开更多
The effects of components and their ratio of grouts on anti-seepage capability of clay-solidified grouting curtain and its permeability of heavy metal cations were investigated by permeating experiments, using reactiv...The effects of components and their ratio of grouts on anti-seepage capability of clay-solidified grouting curtain and its permeability of heavy metal cations were investigated by permeating experiments, using reactive solute transport model to study the permeation of heavy metals (Cd2+, Pb2+ and Hg2+). The study of permeating for different mixture ratios of cement and clay indicates that hydraulic conductivity of clay-solidified grouting curtain with different ratios of solid to liquid or with the same ratio of solid to liquid but with different ratios of cement to clay is changed. The laboratory simulation test results also show that precipitates produced in heavy metal cation migration process in curtain block up water flowing passage which makes the hydraulic conductivity of the solution-permeated curtain decrease with the leakage time. The permeation velocities for different heavy metal cations vary with ionic concentration, exchange capacity and ion radius etc. The test results indicate that the permeation rapidity order of heavy metals cations in clay-solidified grouting curtain is Hg2+>Pb2+ in the same experimental circumstance. In addition, permeability for different mixture ratios and antisepsis capabilities of clay-solidified grouting curtain were studied in tests.展开更多
The adsorption of dedecyltrimethylammoium chloride(DTAC) and hexadecyltrimethylammoium chloride(CTAC) on muscovite mica substrates was examined using atomic force microscopy(AFM). Adsorption morphology images and inte...The adsorption of dedecyltrimethylammoium chloride(DTAC) and hexadecyltrimethylammoium chloride(CTAC) on muscovite mica substrates was examined using atomic force microscopy(AFM). Adsorption morphology images and interaction forces of cationic surfactants at solid-solution interfaces were measured in tapping mode and Pico Force mode, respectively. The images demonstrated that the adsorbed structure was varied by a variety of surfactant concentrations. The adsorbed layer on mica was monolayer at first, and then became bilayer. A striped adsorbed structure was observed in a higher concentration of CTAC,which could not be found in any other concentrations of DTAC. For force measurements, the repulsive force was exponentially decreasing with the concentration increasing till a net attractive force appeared. A largest attractive force could be observed at a certain concentration, which was close to the point of charge neutralization. The results also showed a significant impact of hydrocarbon chain length on adsorption. An adsorption simulation was established to give a clear understanding of the interaction between cationic surfactants and mica.展开更多
OBJECTIVE We want to investigate the mechanism of organophosphate-induced delayed neuropathy(OPIDN) and find appropriate therapeutic medicine.OPIDN,often leads to paresthesias,ataxia and paralysis,occurs in the late-s...OBJECTIVE We want to investigate the mechanism of organophosphate-induced delayed neuropathy(OPIDN) and find appropriate therapeutic medicine.OPIDN,often leads to paresthesias,ataxia and paralysis,occurs in the late-stage of acute poisoning or after repeated exposures to organophosphate(OP) insecticides or nerve agents,and may contribute to the Gulf War Syndrome.METHODS FDSS Ca2^(+)-influx assays,single-cell calcium imaging and patch-clamp electrophysiology were the major testing techniques.Transfected HEK293 cells and dorsal root ganglion(DRG) neurons were used to evaluate the effects of compounds.Wild type and trpa1 knockout mice and adult hyline brown hens were used to evaluate the neuropathological damages caused by the OPs.Transmission electron microscopy imaging was used to observe the nerve injuries ultrastructurally.High-throughput screen for TRPA1 inhibitors was accomplished by Ion Works Barracuda(IWB) automated electrophysiology assay.RESULTS TRPA1(Transient receptor potential cation channel,member A1) channel mediates OPIDN.A variety of OPs,exemplified by malathion,activates TRPA1 but not other neuronal TRP channels.Malathion increases the intracellular calcium levels and upregulates the excitability of mouse DRG neurons in vitro.Mice with repeated exposures to malathion also develop local tissue nerve injuries and pain-related behaviors,which resembles the early symptoms of OPIDN.Both the neuropathological changes and the nocifensive behaviors can be attenuated by treatment of TRPA1 antagonist HC030031 or abolished by knockout of Trpa1 gene.In the classic hens OPIDN model,malathion causes nerve injuries and ataxia to a similar level as the positive inducer tri-ortho-cresyl phosphate(TOCP),which also activates TRPA1 channel.Treatment with HC030031 reduces the damages caused by malathion or TOCP.Duloxetine and Ketotifen,two commercially available drugs exhibiting TRPA1 inhibitory activity,show neuroprotective effects against OPIDN and might be used in emergency situations.CONCLUSION TRPA1 is the major mediator of OPIDN and targeting TRPA1 is an effective way for the treatment of OPIDN.展开更多
Poly(diallyldimethylammonium chloride)(PDDA)is used as organic coagulant in water purification and auxiliary agent in paper production.Determination of PDDA in aqueous solutions is carried out usually by means of poly...Poly(diallyldimethylammonium chloride)(PDDA)is used as organic coagulant in water purification and auxiliary agent in paper production.Determination of PDDA in aqueous solutions is carried out usually by means of polyelectrolyte titration using streaming current detector or o-Toluidine Blue dye for endpoint recognition.The proposed method of PDDA assay takes advantage of Coomassie Brilliant Blue G dye having strong affinity to cationic macromolecules.Titration of PDDA solution with the dye is carried out measuring absorbance at 585nm.Inflection points of the obtained zigzag photometric curves have good repeatability provided that titration rate is low enough to attain endpoint for 1hour or more.The method assures rectilinear calibration(R2=0.999 5)in the broad range of PDDA concentrations from 0.3to 9.6mg·dm^(-3).展开更多
Hydrologic process,turbidity,suspended particles matters(SPM),major cations and TOC concentrations during two storm events in late April 2008 were monitored at Jiangjia Spring which is the outlet of Qingmuguan undergr...Hydrologic process,turbidity,suspended particles matters(SPM),major cations and TOC concentrations during two storm events in late April 2008 were monitored at Jiangjia Spring which is the outlet of Qingmuguan underground river system.Scanning electron microscopy(SEM) and energy disperse spectroscopy(EDS) analyses of SPM were展开更多
Factor Ⅷ deficiency or hemophilia A is X-linkedgenetic disorder in human. General treatment of severehemophilia A consists of adiministration of plasma-derived or recombinant clotting factor concentrates. Ithas cause...Factor Ⅷ deficiency or hemophilia A is X-linkedgenetic disorder in human. General treatment of severehemophilia A consists of adiministration of plasma-derived or recombinant clotting factor concentrates. Ithas caused a series of problems, i. e. viral infection andcost too much to use rF Ⅷ. Nowadays, people havedeveloped the retroviral vector and the adcnoviral展开更多
The development of improved gene transfermethods is a prerequisite for gene therapy to realizeits full potentials. One approach is the design ofplasmid-based delivery system that also termed "self-assembling comp...The development of improved gene transfermethods is a prerequisite for gene therapy to realizeits full potentials. One approach is the design ofplasmid-based delivery system that also termed "self-assembling complexes" such as cationic liposome-DNAcomplex (lipoplex) and protein-DNA complex.Unlike viral vectors, liposome-DNA complexes arenoninfectious, nonimmunogenic and exhibit low展开更多
The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles sh...The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles show the self-aggregation of edge-face in acidic media,the aggregation of edge-face and edge-edge in neutral media,and the dispersion in alkaline media due to electrostatic repulsion. In the presence of the dodecylammonium acetate cationic surfactant and in neutral and alkaline suspension,the hydrophobic aggregation of face-face is demonstrated. The zeta potential of kaolinite increases with increasing the concentration of cationic surfactant. The small and loose aggregation at a low concentration but big and tight aggregation at a high concentration is presented. At pH=7 alkyl quarterly amine salt CTAB has the best hydrophobic aggregation among three cationic surfactants,namely,dodecylammonium acetate,alkyl quarterly amine salts 1227 and CTAB.展开更多
In this study,our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions(SO2-4,Cl-and NO-3) and cations(Na+,NH+4,K+,Mg2+,and Ca2+),nutri...In this study,our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions(SO2-4,Cl-and NO-3) and cations(Na+,NH+4,K+,Mg2+,and Ca2+),nutrients(phosphate and silicate) and hydrogen ion/alkalinity are summarized first.Then,the applications using these methods for monitoring environmental water quality are also presented.For the determination of common anions and cations with nutrients,the separation was successfully performed by a polymethacrylate-based weakly acidic cation-exchange column of TSKgel Super IC-A/C(Tosoh,150 mm×6.0 mm i.d.) and a mixture solution of 100 mmol/L ascorbic acid and 4 mmol/L 18-crown-6 as acidic eluent with dual detection of conductivity and spectrophotometry.For the determination of hydrogen ion/alkalinity,the separation was conducted by TSKgel ODS-100Z column(Tosoh,150 mm×4.5 mm i.d.) modified with lithium dodecylsulfate and an eluent of 40 mmol/L LiCl/0.1 mmol/L lithium dodecylsulfate/0.05 mmol/L H2SO4 with conductivity detector.The differences of ion concentration between untreated and treated wastewater showed the variation of ionic species during biological treatment process in a sewage treatment plant.Occurrence and distribution of water-quality conditions were related to the bioavailability and human activity in watershed.From these results,our advanced ion chromatographic methods have contributed significantly for water quality monitoring of environmental waters.展开更多
A unified ion-exclusion chromatography(IEC) system for monitoring anionic and cationic nutrients like NH + 4,NO 2,NO 3,phosphate ion,silicate ion and HCO 3 was developed and applied to several environmental waters.The...A unified ion-exclusion chromatography(IEC) system for monitoring anionic and cationic nutrients like NH + 4,NO 2,NO 3,phosphate ion,silicate ion and HCO 3 was developed and applied to several environmental waters.The IEC system consisted of four IEC methodologies,including the IEC with ultraviolet(UV) detection at 210 nm for determining NH + 4 on anion-exchange separation column in OH form connected with anion-exchange UV-conversion column in I form in tandem,the IEC with UV-detection at 210 nm for determining simultaneously NO 2 and NO 3 on cation-exchange separation column in H + form,the IEC with UV-detection at 210 nm for determining HCO 3 on cation-exchange separation column in H + form connected with anion-exchange UV-conversion column in I form in tandem,and the IEC with visible-detection based on molybdenum-blue reaction for determining simultaneously silicate and phosphate ions on cation-exchange separation column in H + form.These IEC systems were combined through three manually-driven 6-port column selection valves to select each separation column to determine selectively the ionic nutrients.Using this sequential water quality monitoring system,the analytical performances such as calibration linearity,reproducibility,detection limit and recovery were also tested under the optimized chromatographic conditions.This novel water quality monitoring system has been applied successfully for the determination of the ionic eutrophication components in sub-urban river waters.展开更多
The impregnations of different kinds of titania support with aqueous solution or ferricions at various pH values and with the solution of these ions in a polar aprotic solvent,dimethylformamide(DMF),were invcstigated....The impregnations of different kinds of titania support with aqueous solution or ferricions at various pH values and with the solution of these ions in a polar aprotic solvent,dimethylformamide(DMF),were invcstigated.The results suggest that the surface ofhydrated titania is amphoteric,and has the function of a cationic exchanger,its ion ex-change properties arc dependent on the pH of the impregnating solutions.The higher theconcentration of metal ions in the impregnating solution and the more polar thc solvent,thehigher the loading on the support material having thc higher degree of crystallinity and alarger surface area without any pretreatments such as dehydration and calcination.展开更多
基金supported by the National Natural Science Foundation of China(No.21875110,22075143)the Science Challenge Project(No.TZ2018004)the Qing Lan Project for the grant。
文摘Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole(1)and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4]triazolo[4,3-b][1,2,4]triazole(9)were synthesized through the convenient cyclization reaction from the readily available reactant.Their energetic salts with high nitrogen content were proved to be rare examples of divalent monocyclic/fused cyclic cationic salts according to the single crystal analyses.The structure of intermediate B was also identified and verified by its trivalent cation crystal 17.5H_2O indirectly.Energetic compounds 2-8 and 10-17 were fully characterized by NMR spectroscopy,infrared spectroscopy,differential scanning calorimetry,elemental analysis.These energetic salts exhibit good thermal stability with decomposition temperatures ranged from 182℃to 245℃.The sensitivity of compounds 2,6,10 and 14 is similar or superior to that of RDX while the others were much more insensitive to mechanical stimulate.Furthermore,detonation velocity of 10(8843 m/s)surpass that of RDX(D=8795 m/s).Considering the high gas production volume(≥808 L/kg)of 2,4,10and 12,constant-volume combustion experiments were conduct to evaluate their gas production capacities specifically.These compounds possess much higher maximum gas-production pressures(P_(max):7.88-10.08 MPa)than the commonly used reagent guanidine nitrate(GN:P_(max)=4.20 MPa),which indicate their strong gas production capacity.
文摘The mixed lineage kinase domain-like(MLKL)protein is a key factor in tumor necrosis factor-induced necroptosis.Recent studies on necroptosis execution revealed a commitment role of MLKL in membrane disruption.However,our knowledge of how MLKL functions on membrane remains very limited.Here we demonstrate that MLKL forms cation channels that are permeable preferential y to Mg2+rather than Ca2+in the presence of Na+and K+.Moreover,the N-terminal domain containing six helices(H1-H6)is sufficient to form channels.Using the substituted cysteine accessibility method,we further determine that helix H1,H2,H3,H5 and H6 are transmembrane segments,while H4 is located in the cytoplasm.Finally,MLKL-induced membrane depolarization and cell death exhibit a positive correlation to its channel activity.The Mg2+-preferred permeability and five transmembrane segment topology distinguish MLKL from previously identified Mg2+-permeable channels and thus establish MLKL as a novel class of cation channels.
文摘As a strategy for phytopathogen control throughtransgenic way,antimicrobial peptide genes havebeen employed over the last two decades.CEMA is a cationic antimicrobial chimericpeptide,which is produced by fusing eightamino acid residues from the antimicrobialpeptide ceropin A with a modified meltin.Threetransgenic cotton plants were generated
文摘The most remarkable effect in spinel ferrites is the strong dependence of properties on the state of structural disorder and,in particular,on the cation distribution.The structural characterization of a Co-Zn ferrite nanoparticle sample was reported which prepared by wet chemical co-precipitation method.The samples were sintered at three different temperatures viz.650℃,850℃ and 1050℃ for 12 h.The structural details like:lattice constant and distribution of cations in the tetrahedral and octahedral interstitial voids have been deduced through X-ray diffraction (XRD) data analysis.Lattice constant was found to increase with the increase in Zn2+ ions and sintering temperature.Theoretical intensity ratios of (220),(400),(440) planes were considered,as these reflections are sensitive to cations on the A and B sites.Close agreement of the theoretical intensity ratio with the intensity ratio observed from XRD pattern supports the occupancy of Zn2+ ions and Co2+ ions on the octahedral and tetrahedral sites,respectively.
基金supported by State Key Program of Basic Research of China(2013CB910604)National Natural Science Foundation of China(61327014,61175103,61433017 and31571427)the External Cooperation Program of BIC,Chinese Academy of Sciences(1536631KYSB20130003)
文摘OBJECTIVE To investigate how MLKL functions on the membrane and explore its electrophysiological characters and structure.METHODS The full-length human MLKL were expressed in SF21 cells and purified using glutathione-sepharose affinity chromatography.The currents of purified MLKL proteins were recorded in avoltage-clamp mode using a Warner BC-535 bilayer clamp amplifier.The currents were digitized using p CLAMP 10.2 software.HEK293 cells were cultured and transfected with MLKL plasmid.Cell viability was examined using the Cell Titer-Glo Luminescent Cell Viability Assay kit.RESULT MLKL forms cation channels that are permeable preferentially to Mg2+rather than Ca2+in the presence of Na+and K+.Moreover,each MLKL monomer contains five transmembrane helices:H1,H2,H3,H5 and H6 of the N-terminal domain which is sufficient to form channels.Finally,MLKL-induced membrane depolarization and cell death exhibit a positive correlation to its channel activity.
基金Project(2020YFC1909805)supported by the National Key Research and Development Program of ChinaProjects(51504293,51574284)supported by the National Natural Science Foundation of China+2 种基金Project(2018-GX-A7)supported by Qinghai Provincial Major Scientific and Technological Special Project of ChinaProject(2020SK2125)supported by the Key Research and Development Program of Hunan Province,ChinaProject(CSUZC202129)supported by Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,China。
文摘Zinc extraction from crude zinc oxide(CZO)is beneficial to the full utilization of secondary resources and environmental protection.In this paper,a systematic investigation was carried out to study the leaching behavior of CZO by using ammonia-ammonium carbonate solution.It was found that the maximum leaching rate of zinc from CZO dust was 95.7%under the conditions of[Zn]T:[NH 3]T:[CO_(3)^(2−)]=1:7.00:1.75,liquid to solid ratio 5:1,leaching temperature 30℃ and leaching time 60 min.Compared with pure zinc oxide(PZO)leaching,the CZO leaching required longer time and more leaching agents,which is caused by the Cd^(2+),Pb^(2+) and other metal cationic impurities in CZO.The metal cationic impurities dissolved in the leaching solution and combined with ammonium to form complexes,consuming leaching agents and affecting zinc leaching.
文摘The effects of components and their ratio of grouts on anti-seepage capability of clay-solidified grouting curtain and its permeability of heavy metal cations were investigated by permeating experiments, using reactive solute transport model to study the permeation of heavy metals (Cd2+, Pb2+ and Hg2+). The study of permeating for different mixture ratios of cement and clay indicates that hydraulic conductivity of clay-solidified grouting curtain with different ratios of solid to liquid or with the same ratio of solid to liquid but with different ratios of cement to clay is changed. The laboratory simulation test results also show that precipitates produced in heavy metal cation migration process in curtain block up water flowing passage which makes the hydraulic conductivity of the solution-permeated curtain decrease with the leakage time. The permeation velocities for different heavy metal cations vary with ionic concentration, exchange capacity and ion radius etc. The test results indicate that the permeation rapidity order of heavy metals cations in clay-solidified grouting curtain is Hg2+>Pb2+ in the same experimental circumstance. In addition, permeability for different mixture ratios and antisepsis capabilities of clay-solidified grouting curtain were studied in tests.
基金Project(50974134)supported by the National Natural Science Foundation of China
文摘The adsorption of dedecyltrimethylammoium chloride(DTAC) and hexadecyltrimethylammoium chloride(CTAC) on muscovite mica substrates was examined using atomic force microscopy(AFM). Adsorption morphology images and interaction forces of cationic surfactants at solid-solution interfaces were measured in tapping mode and Pico Force mode, respectively. The images demonstrated that the adsorbed structure was varied by a variety of surfactant concentrations. The adsorbed layer on mica was monolayer at first, and then became bilayer. A striped adsorbed structure was observed in a higher concentration of CTAC,which could not be found in any other concentrations of DTAC. For force measurements, the repulsive force was exponentially decreasing with the concentration increasing till a net attractive force appeared. A largest attractive force could be observed at a certain concentration, which was close to the point of charge neutralization. The results also showed a significant impact of hydrocarbon chain length on adsorption. An adsorption simulation was established to give a clear understanding of the interaction between cationic surfactants and mica.
基金supported by National Key Scientific Instrument&Equipment Development Program of China(2012YQ03026010)the Joint NSFC-ISF Research Program(8146114802)+2 种基金jointly funded by the National Natural Science Foundation of China and the Israel Science Foundationthe State Key Program of Basic Research of China(2013CB910604)the National Natural Science Foundation of China(61327014 and 61175103)
文摘OBJECTIVE We want to investigate the mechanism of organophosphate-induced delayed neuropathy(OPIDN) and find appropriate therapeutic medicine.OPIDN,often leads to paresthesias,ataxia and paralysis,occurs in the late-stage of acute poisoning or after repeated exposures to organophosphate(OP) insecticides or nerve agents,and may contribute to the Gulf War Syndrome.METHODS FDSS Ca2^(+)-influx assays,single-cell calcium imaging and patch-clamp electrophysiology were the major testing techniques.Transfected HEK293 cells and dorsal root ganglion(DRG) neurons were used to evaluate the effects of compounds.Wild type and trpa1 knockout mice and adult hyline brown hens were used to evaluate the neuropathological damages caused by the OPs.Transmission electron microscopy imaging was used to observe the nerve injuries ultrastructurally.High-throughput screen for TRPA1 inhibitors was accomplished by Ion Works Barracuda(IWB) automated electrophysiology assay.RESULTS TRPA1(Transient receptor potential cation channel,member A1) channel mediates OPIDN.A variety of OPs,exemplified by malathion,activates TRPA1 but not other neuronal TRP channels.Malathion increases the intracellular calcium levels and upregulates the excitability of mouse DRG neurons in vitro.Mice with repeated exposures to malathion also develop local tissue nerve injuries and pain-related behaviors,which resembles the early symptoms of OPIDN.Both the neuropathological changes and the nocifensive behaviors can be attenuated by treatment of TRPA1 antagonist HC030031 or abolished by knockout of Trpa1 gene.In the classic hens OPIDN model,malathion causes nerve injuries and ataxia to a similar level as the positive inducer tri-ortho-cresyl phosphate(TOCP),which also activates TRPA1 channel.Treatment with HC030031 reduces the damages caused by malathion or TOCP.Duloxetine and Ketotifen,two commercially available drugs exhibiting TRPA1 inhibitory activity,show neuroprotective effects against OPIDN and might be used in emergency situations.CONCLUSION TRPA1 is the major mediator of OPIDN and targeting TRPA1 is an effective way for the treatment of OPIDN.
文摘Poly(diallyldimethylammonium chloride)(PDDA)is used as organic coagulant in water purification and auxiliary agent in paper production.Determination of PDDA in aqueous solutions is carried out usually by means of polyelectrolyte titration using streaming current detector or o-Toluidine Blue dye for endpoint recognition.The proposed method of PDDA assay takes advantage of Coomassie Brilliant Blue G dye having strong affinity to cationic macromolecules.Titration of PDDA solution with the dye is carried out measuring absorbance at 585nm.Inflection points of the obtained zigzag photometric curves have good repeatability provided that titration rate is low enough to attain endpoint for 1hour or more.The method assures rectilinear calibration(R2=0.999 5)in the broad range of PDDA concentrations from 0.3to 9.6mg·dm^(-3).
文摘Hydrologic process,turbidity,suspended particles matters(SPM),major cations and TOC concentrations during two storm events in late April 2008 were monitored at Jiangjia Spring which is the outlet of Qingmuguan underground river system.Scanning electron microscopy(SEM) and energy disperse spectroscopy(EDS) analyses of SPM were
文摘Factor Ⅷ deficiency or hemophilia A is X-linkedgenetic disorder in human. General treatment of severehemophilia A consists of adiministration of plasma-derived or recombinant clotting factor concentrates. Ithas caused a series of problems, i. e. viral infection andcost too much to use rF Ⅷ. Nowadays, people havedeveloped the retroviral vector and the adcnoviral
文摘The development of improved gene transfermethods is a prerequisite for gene therapy to realizeits full potentials. One approach is the design ofplasmid-based delivery system that also termed "self-assembling complexes" such as cationic liposome-DNAcomplex (lipoplex) and protein-DNA complex.Unlike viral vectors, liposome-DNA complexes arenoninfectious, nonimmunogenic and exhibit low
基金Project(2005CB623701) supported by the Major State Basic Research Development Program of China
文摘The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles show the self-aggregation of edge-face in acidic media,the aggregation of edge-face and edge-edge in neutral media,and the dispersion in alkaline media due to electrostatic repulsion. In the presence of the dodecylammonium acetate cationic surfactant and in neutral and alkaline suspension,the hydrophobic aggregation of face-face is demonstrated. The zeta potential of kaolinite increases with increasing the concentration of cationic surfactant. The small and loose aggregation at a low concentration but big and tight aggregation at a high concentration is presented. At pH=7 alkyl quarterly amine salt CTAB has the best hydrophobic aggregation among three cationic surfactants,namely,dodecylammonium acetate,alkyl quarterly amine salts 1227 and CTAB.
基金supported by the Chugoku Regional Development Bureau of the Ministry of Land,Infrastructure,Transport and Tourism,Japan
文摘In this study,our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions(SO2-4,Cl-and NO-3) and cations(Na+,NH+4,K+,Mg2+,and Ca2+),nutrients(phosphate and silicate) and hydrogen ion/alkalinity are summarized first.Then,the applications using these methods for monitoring environmental water quality are also presented.For the determination of common anions and cations with nutrients,the separation was successfully performed by a polymethacrylate-based weakly acidic cation-exchange column of TSKgel Super IC-A/C(Tosoh,150 mm×6.0 mm i.d.) and a mixture solution of 100 mmol/L ascorbic acid and 4 mmol/L 18-crown-6 as acidic eluent with dual detection of conductivity and spectrophotometry.For the determination of hydrogen ion/alkalinity,the separation was conducted by TSKgel ODS-100Z column(Tosoh,150 mm×4.5 mm i.d.) modified with lithium dodecylsulfate and an eluent of 40 mmol/L LiCl/0.1 mmol/L lithium dodecylsulfate/0.05 mmol/L H2SO4 with conductivity detector.The differences of ion concentration between untreated and treated wastewater showed the variation of ionic species during biological treatment process in a sewage treatment plant.Occurrence and distribution of water-quality conditions were related to the bioavailability and human activity in watershed.From these results,our advanced ion chromatographic methods have contributed significantly for water quality monitoring of environmental waters.
基金financially supported from TOSOH Corporation and Fellowships Program for Young Scientists of the Japan Society for the Promotion of Science on FY2011
文摘A unified ion-exclusion chromatography(IEC) system for monitoring anionic and cationic nutrients like NH + 4,NO 2,NO 3,phosphate ion,silicate ion and HCO 3 was developed and applied to several environmental waters.The IEC system consisted of four IEC methodologies,including the IEC with ultraviolet(UV) detection at 210 nm for determining NH + 4 on anion-exchange separation column in OH form connected with anion-exchange UV-conversion column in I form in tandem,the IEC with UV-detection at 210 nm for determining simultaneously NO 2 and NO 3 on cation-exchange separation column in H + form,the IEC with UV-detection at 210 nm for determining HCO 3 on cation-exchange separation column in H + form connected with anion-exchange UV-conversion column in I form in tandem,and the IEC with visible-detection based on molybdenum-blue reaction for determining simultaneously silicate and phosphate ions on cation-exchange separation column in H + form.These IEC systems were combined through three manually-driven 6-port column selection valves to select each separation column to determine selectively the ionic nutrients.Using this sequential water quality monitoring system,the analytical performances such as calibration linearity,reproducibility,detection limit and recovery were also tested under the optimized chromatographic conditions.This novel water quality monitoring system has been applied successfully for the determination of the ionic eutrophication components in sub-urban river waters.
文摘The impregnations of different kinds of titania support with aqueous solution or ferricions at various pH values and with the solution of these ions in a polar aprotic solvent,dimethylformamide(DMF),were invcstigated.The results suggest that the surface ofhydrated titania is amphoteric,and has the function of a cationic exchanger,its ion ex-change properties arc dependent on the pH of the impregnating solutions.The higher theconcentration of metal ions in the impregnating solution and the more polar thc solvent,thehigher the loading on the support material having thc higher degree of crystallinity and alarger surface area without any pretreatments such as dehydration and calcination.
