Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhi...Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.展开更多
AIM To assess the direct effects of ischemia onintestinal epithelial integrity. Furthermore, clinicalefforts at mitigating the effect of hypoperfusion on gutpermeability have focused on restoring gut vascularfunction....AIM To assess the direct effects of ischemia onintestinal epithelial integrity. Furthermore, clinicalefforts at mitigating the effect of hypoperfusion on gutpermeability have focused on restoring gut vascularfunction.METHODS： we report that, in the Caco-2 cell modelof transepithelial transport, calcium glycerophosphate（CGP）, an inhibitor of intestinal alkaline phosphataseF3, has a significant effect to preserve transepithelialelectrical resistance （TEER） and to attenuate increasesin mannitol flux rates during hypoxia or cytokinestimulation.RESULTS： The effect was observable even at concentrationsas low as 1 μmol/L. As celiac disease is alsomarked by a loss of gut epithelial integrity, the effectof CGP to attenuate the effect of the α-gliadin peptide31-55 was also examined. In this instance, CGP exertedlittle effect of preservation of TEER, but significantlyattenuated peptide induced increase in mannitol flux.CONCLUSION： it appears that CGP treatment mightsynergize with other therapies to preserve gut epithelialintegrity.展开更多
The chitosan/β-glycerophosphate( CS/β-GP),a physical hydrogel system with thermosensitive and injectable features combined with biocompatibility and biodegradability, has great potentials as matrices for drug or cel...The chitosan/β-glycerophosphate( CS/β-GP),a physical hydrogel system with thermosensitive and injectable features combined with biocompatibility and biodegradability, has great potentials as matrices for drug or cell encapsulation and delivery,or as in situ gel-forming materials for tissue repair. Here,the chitin nanocrystal( Chi NC) was introduced into the aforementioned system, and its effects on solution behavior and mechanical properties was investigated. The results showed the incorporation of Chi NC complicated sol-to-gel transition process; a higher loading ratio( 20%) speeded up sol-to-gel transition rate,reduced the solto-gel transition temperature,while still maintained shear-thinning behavior or injectable feature. Moreover,the mechanical properties of gels were significantly enhanced by Chi NC, accompanied by decreased water uptake. The above mentioned behavior favored better applications as injectable tissue-repair implants.展开更多
β-GP influences on rat osteoblast development at the early period of culture i.e , the non-mineralization phase, and changes with the different cell passages were investigated. Alkaline phosphatase (ALP) was chosen a...β-GP influences on rat osteoblast development at the early period of culture i.e , the non-mineralization phase, and changes with the different cell passages were investigated. Alkaline phosphatase (ALP) was chosen as a main object. Northern blot analysis revealed up to two-fold increase in the steady statelevel of ALP mRNA after stimulation of rat osteoblast with 10 mM β-GP- Likewise, 10 mM β-GP induced a 10─30 % increase in ALP activity (P< 0. 01) of early passages (1 to 4), but not of later passages (5 to 6). The β-GP induced increase in ALP activity was totally inhibited by the protein synthesis inhibitor, cycloheximide (50 μM).β- GP stimulation was found to be without effect on cell proliferation measured as 3H-thymidine incorporation. It is concluded that β-GP has no effect on proliferation but induces an increase in both mRNA level and activity of ALP in the non-mineralization phase of cultures of fetal rat calvarial cells , which lasts for several passages but will disappear in older cultures.展开更多
The photochemical reaction process of anthraquinone-2-sodium sulfonate （AQS） in the mixture of water （H2O） and N-butylpyridinium tetrafluoroborate （[BPy] [BF4]） was studied using the laser flash photolysis techn...The photochemical reaction process of anthraquinone-2-sodium sulfonate （AQS） in the mixture of water （H2O） and N-butylpyridinium tetrafluoroborate （[BPy] [BF4]） was studied using the laser flash photolysis technique. Experimental results show that the excited triplet of AQS （3AQS＊） could react rapidly with H2O and the transient absorption spectra greatly changed by increasing the volume fraction of the ionic liquid （VIL） in [BPy][BF4]/H2O mixtures. The absorbance at 510 nm increased gradually with increasing VIL when 0〈VIL〈0.1. By contrast, the absorbance decreased gradually when VIL〉0.1. Otherwise, the absorbance of the band near 380 nm steadily increased. The apparent kinetic parameters of transient species B and ^3AQS＊ are obtained approximately. 3AQS＊ abstracting hydrogen from [BPy]＋ was also explored. It was deduced that the 350-420 nm band was the superposition of the peaks of 3AQS＊ and AQSH＇. The two reactions of 3AQS＊ with [BPy][BF4] and H2O are a pair of competitive reactions. We also concluded that the entire reaction processes slow down in the case of high [BPy] [BF4] concentrations.展开更多
BACKGROUND： This study was undertaken to investigate the expression of hypoxia-inducible factor-1α （HIF-1α） in rat cerebral cortex and the effects of β-sodium aescinate （SA） administration after return of spon...BACKGROUND： This study was undertaken to investigate the expression of hypoxia-inducible factor-1α （HIF-1α） in rat cerebral cortex and the effects of β-sodium aescinate （SA） administration after return of spontaneous circulation （ROSC）.METHODS： Sixty rats were divided into three groups： SA group, injected intraperitoneally with SA instantly after ROSC; control group, injected intraperitoneally with normal saline; and sham-operated group, without cardiac arrest or SA. The cardiac arrest model was established using asphyxiation and intravenous potassium chloride. Blood was sampled 1, 6, 12, and 24 hours after ROSC. Protein and mRNA levels of HIF-1α, VEGF and EPO were detected in the cerebral cortex by immunohistochemistry and real-time RT-PCR; serum levels of NSE and S100β were determined by enzyme-linked immunosorbent assays.RESULTS： Serum S100β and NSE were signi？ cantly increased in the control group versus the sham-operated group 1, 6, 12 and 24 hours after ROSC （P〈0.05）. Protein and mRNA levels of HIF-1α, VEGF and EPO were signi？ cantly increased in the control rats （P〈0.05）. Serum NSE and S100β were significantly decreased in the SA group versus the control group 1, 6, 12 and 24 hours after ROSC （P〈0.05）. Protein and mRNA levels of HIF-1α, VEGF and EPO were signi？ cantly increased in the SA group （P〈0.05）.CONCLUSIONS： The expression of HIF-1α is increased in rat cerebral cortex after ROSC, and SA up-regulates the expression of HIF-1α. The up-regulation of HIF-1α improves the resistance of the cortex to ischemia and hypoxia and contributes to neuroprotection, possibly because of up-regulation of EPO and VEGF expression.展开更多
The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was ...The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was prepared instanteously through the reaction of thiolactic acid with NaOH. Mono and dinuclear complexes were obtained by direct reaction of the above ligands with H[AuCI4] in 1 ： 1, 2：1, 1：2, 2：2 and 3：1 ligands to metal molar ratio. The prepared complexes were characterized by elemental analysis, spectral studies FTIR （Fourier transform Infrared） and UV-Vis, magnetic measurement, conductivity measurement and IHNMR for the ligand （L） and some of the complexes. The conductance data indicate that the complexes of the formulas Na[Au（SCH3CHCOO）2], Na[Au（SCH3CHCOO）（OOCCHCH3SH）2] and [Au（L）]Cl are 1：1 electrolyte. Electronic spectra and magnetic moment values indicate the presence of square planner geometry around Au（III） ions.展开更多
Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo g...Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra展开更多
基金the financial support from the National Key Research and Development Program of China(No.2018YFC1903403)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.
文摘AIM To assess the direct effects of ischemia onintestinal epithelial integrity. Furthermore, clinicalefforts at mitigating the effect of hypoperfusion on gutpermeability have focused on restoring gut vascularfunction.METHODS： we report that, in the Caco-2 cell modelof transepithelial transport, calcium glycerophosphate（CGP）, an inhibitor of intestinal alkaline phosphataseF3, has a significant effect to preserve transepithelialelectrical resistance （TEER） and to attenuate increasesin mannitol flux rates during hypoxia or cytokinestimulation.RESULTS： The effect was observable even at concentrationsas low as 1 μmol/L. As celiac disease is alsomarked by a loss of gut epithelial integrity, the effectof CGP to attenuate the effect of the α-gliadin peptide31-55 was also examined. In this instance, CGP exertedlittle effect of preservation of TEER, but significantlyattenuated peptide induced increase in mannitol flux.CONCLUSION： it appears that CGP treatment mightsynergize with other therapies to preserve gut epithelialintegrity.
基金National Natural Science Foundation of China(No.51303024)
文摘The chitosan/β-glycerophosphate( CS/β-GP),a physical hydrogel system with thermosensitive and injectable features combined with biocompatibility and biodegradability, has great potentials as matrices for drug or cell encapsulation and delivery,or as in situ gel-forming materials for tissue repair. Here,the chitin nanocrystal( Chi NC) was introduced into the aforementioned system, and its effects on solution behavior and mechanical properties was investigated. The results showed the incorporation of Chi NC complicated sol-to-gel transition process; a higher loading ratio( 20%) speeded up sol-to-gel transition rate,reduced the solto-gel transition temperature,while still maintained shear-thinning behavior or injectable feature. Moreover,the mechanical properties of gels were significantly enhanced by Chi NC, accompanied by decreased water uptake. The above mentioned behavior favored better applications as injectable tissue-repair implants.
文摘β-GP influences on rat osteoblast development at the early period of culture i.e , the non-mineralization phase, and changes with the different cell passages were investigated. Alkaline phosphatase (ALP) was chosen as a main object. Northern blot analysis revealed up to two-fold increase in the steady statelevel of ALP mRNA after stimulation of rat osteoblast with 10 mM β-GP- Likewise, 10 mM β-GP induced a 10─30 % increase in ALP activity (P< 0. 01) of early passages (1 to 4), but not of later passages (5 to 6). The β-GP induced increase in ALP activity was totally inhibited by the protein synthesis inhibitor, cycloheximide (50 μM).β- GP stimulation was found to be without effect on cell proliferation measured as 3H-thymidine incorporation. It is concluded that β-GP has no effect on proliferation but induces an increase in both mRNA level and activity of ALP in the non-mineralization phase of cultures of fetal rat calvarial cells , which lasts for several passages but will disappear in older cultures.
基金This work was supported by the National Natural Science Foundation of China （No.21173002） and the Anhui Provincial Natural Science Foundation, China （No.1308085MB20）.
文摘The photochemical reaction process of anthraquinone-2-sodium sulfonate （AQS） in the mixture of water （H2O） and N-butylpyridinium tetrafluoroborate （[BPy] [BF4]） was studied using the laser flash photolysis technique. Experimental results show that the excited triplet of AQS （3AQS＊） could react rapidly with H2O and the transient absorption spectra greatly changed by increasing the volume fraction of the ionic liquid （VIL） in [BPy][BF4]/H2O mixtures. The absorbance at 510 nm increased gradually with increasing VIL when 0〈VIL〈0.1. By contrast, the absorbance decreased gradually when VIL〉0.1. Otherwise, the absorbance of the band near 380 nm steadily increased. The apparent kinetic parameters of transient species B and ^3AQS＊ are obtained approximately. 3AQS＊ abstracting hydrogen from [BPy]＋ was also explored. It was deduced that the 350-420 nm band was the superposition of the peaks of 3AQS＊ and AQSH＇. The two reactions of 3AQS＊ with [BPy][BF4] and H2O are a pair of competitive reactions. We also concluded that the entire reaction processes slow down in the case of high [BPy] [BF4] concentrations.
基金supported by the Liaoning Province Natural Science Foundation(20092162)
文摘BACKGROUND： This study was undertaken to investigate the expression of hypoxia-inducible factor-1α （HIF-1α） in rat cerebral cortex and the effects of β-sodium aescinate （SA） administration after return of spontaneous circulation （ROSC）.METHODS： Sixty rats were divided into three groups： SA group, injected intraperitoneally with SA instantly after ROSC; control group, injected intraperitoneally with normal saline; and sham-operated group, without cardiac arrest or SA. The cardiac arrest model was established using asphyxiation and intravenous potassium chloride. Blood was sampled 1, 6, 12, and 24 hours after ROSC. Protein and mRNA levels of HIF-1α, VEGF and EPO were detected in the cerebral cortex by immunohistochemistry and real-time RT-PCR; serum levels of NSE and S100β were determined by enzyme-linked immunosorbent assays.RESULTS： Serum S100β and NSE were signi？ cantly increased in the control group versus the sham-operated group 1, 6, 12 and 24 hours after ROSC （P〈0.05）. Protein and mRNA levels of HIF-1α, VEGF and EPO were signi？ cantly increased in the control rats （P〈0.05）. Serum NSE and S100β were significantly decreased in the SA group versus the control group 1, 6, 12 and 24 hours after ROSC （P〈0.05）. Protein and mRNA levels of HIF-1α, VEGF and EPO were signi？ cantly increased in the SA group （P〈0.05）.CONCLUSIONS： The expression of HIF-1α is increased in rat cerebral cortex after ROSC, and SA up-regulates the expression of HIF-1α. The up-regulation of HIF-1α improves the resistance of the cortex to ischemia and hypoxia and contributes to neuroprotection, possibly because of up-regulation of EPO and VEGF expression.
文摘The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was prepared instanteously through the reaction of thiolactic acid with NaOH. Mono and dinuclear complexes were obtained by direct reaction of the above ligands with H[AuCI4] in 1 ： 1, 2：1, 1：2, 2：2 and 3：1 ligands to metal molar ratio. The prepared complexes were characterized by elemental analysis, spectral studies FTIR （Fourier transform Infrared） and UV-Vis, magnetic measurement, conductivity measurement and IHNMR for the ligand （L） and some of the complexes. The conductance data indicate that the complexes of the formulas Na[Au（SCH3CHCOO）2], Na[Au（SCH3CHCOO）（OOCCHCH3SH）2] and [Au（L）]Cl are 1：1 electrolyte. Electronic spectra and magnetic moment values indicate the presence of square planner geometry around Au（III） ions.
文摘Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra
