Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain fo...Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain for low-salt aqueous electrolytes operating at high voltage and low temperature.Herein,we report a low-salt(0.87 m,m means mol kg^(-1))'salt in dimethyl sulfoxide/water'hybrid electrolyte with non-flammability via hybridizing aqueous electrolyte with an organic co-solvent of dimethyl sulfoxide(hydrogen bond acceptor).As a result,the 0.87 m hybrid electrolyte exhibits enhanced electrochemical stability,a freezing temperature below-50℃,and an outstanding ionic conductivity of 0.52mS cm~(-1)at-50℃.Dimethyl sulfoxide can anchor water molecules through intermolecular hydrogen bond interaction,effectively reinforcing the stability of water in the hybrid electrolyte.Furthermore,the interaction between dimethyl sulfoxide and water molecules diminishes the involvement of water in the generation of ordered ice crystals,finally facilitating the low-temperature performance of the hybrid electrolyte.When paired with the 0.87 m'salt in dimethyl sulfoxide/water'hybrid electrolyte,the symmetric supercapacitor presents a 2.0 V high operating voltage at 25℃,and can operate stably at-50℃.Importantly,the suppressed electrochemical reaction of water at-50℃further leads to the symmetric supercapacitor operated at a higher voltage of 2.6 V.This modification strategy opens an effective avenue to develop low-salt electrolytes for high-voltage and low-temperature aqueous supercapacitors.展开更多
AIM: To investigate whether dimethyl sulfoxide(DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatoryresponse syndrome and multiple organ dysfunction syndrome.METHODS: ...AIM: To investigate whether dimethyl sulfoxide(DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatoryresponse syndrome and multiple organ dysfunction syndrome.METHODS: Sprague-Dawley rats were randomly divided into four groups: sham with administration of normal saline(SS group); sham with administration of DMSO(SD group); zymosan with administration of normal saline(ZS group); and zymosan with administration of DMSO(ZD group). Each group contained three subgroups according to 4 h,8 h,and 24 h after surgery. At 4 h,8 h,and 24 h after intraperitoneal injection of zymosan(750 mg/kg),the levels of intestinal inflammatory cytokines [tumor necrosis factor-alpha(TNF-α) and interleukin(IL)-10] and oxides(myeloperoxidase,malonaldehyde,and superoxide dismutase) were examined. The levels of diamine oxidase(DAO) in plasma and intestinal mucosal blood flow(IMBF) were determined. Intestinal injury was also evaluated using an intestinal histological score and apoptosis of intestinal epithelial cells was determined by deoxynucleotidyl transferase d UTP nick end labeling(TUNEL) assay. The intestinal epithelial tight junction protein,ZO-1,was observed by immunofluorescence.RESULTS: DMSO decreased TNF-α and increased IL-10 levels in the intestine compared with the ZS group at the corresponding time points. The activity of intestinal myeloperoxidase in the ZS group was higher than that in the ZD group 24 h after zymosan administration(P < 0.05). DMSO decreased the content of malondialdehyde(MDA) and increased the activity of superoxide dehydrogenase(SOD) 24 h after zymosan administration. The IMBF was lowest at 24 h and was 49.34% and 58.26% in the ZS group and ZD group,respectively(P < 0.05). DMSO alleviated injury in intestinal villi,and the gut injury score was significantly lower than the ZS group(3.6 ± 0.2 vs 4.2 ± 0.3,P < 0.05). DMSO decreased the level of DAO in plasma compared with the ZS group(65.1 ± 4.7 U/L vs 81.1 ± 5.0 U/L,P < 0.05). DMSO significantly preserved ZO-1 protein expression and localization 24 h after zymosan administration. The TUNEL analysis indicated that the number of apoptotic intestinal cells in the ZS group was much higher than the ZD group(P < 0.05).CONCLUSION: DMSO inhibited intestinal cytokines and protected against zymosan-induced gut barrier dysfunction.展开更多
The work presents density(ρ) and viscosity(η) data of binary system polyethylene glycol 600(PEG) + dimethyl sulfoxide(DMSO) over the entire concentration range at T =(298.15, 303.15, 308.15, 313.15 and 318.15) K and...The work presents density(ρ) and viscosity(η) data of binary system polyethylene glycol 600(PEG) + dimethyl sulfoxide(DMSO) over the entire concentration range at T =(298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. On the basis of density and viscosity values, the excess properties of PEG(1) + DMSO(2) mixtures, including excess molar volume(V_m^E), viscosity deviation(Δη), excess free energies of activation(ΔG^(*E)), and isobaric thermal expansion coefficient(αp), were calculated. At the same time, in order to conjecture the density viscosity under different conditions, the density and viscosity data were fitted with the corresponding formula. The calculated results of V_m^E, Δη, and ΔG^(*E) were fitted with the Redlich–Kister equation to derive coefficients and estimate the standard deviations(σ) between the experimental and calculated values. Moreover, the intermolecular interaction of PEG with DMSO was discussed on the basis of FTIR and UV–Vis spectral results of PEG(1) + DMSO(2) mixtures. The results indicated that there were the hydrogen bonding and interactions of hydroxyl hydrogen atoms in PEG with oxygen atoms in DMSO.展开更多
A novel one-dimensional chain complex [Pr2(bnbo)6(DMSO)4] (bnbo=3,5-binitro benzoyloxy, DMSO= dimethyl sulfoxide) with bridging carboxyl groups was synthesized and its structure has been determined by single-crystal X...A novel one-dimensional chain complex [Pr2(bnbo)6(DMSO)4] (bnbo=3,5-binitro benzoyloxy, DMSO= dimethyl sulfoxide) with bridging carboxyl groups was synthesized and its structure has been determined by single-crystal X-ray methods. In the complex, a pair of adjacent metal ions are alternately connected by four or two carboxylate groups to form an infinite chain of 8-coordinated Pr3+ ions. The complex (Pr2C50H42N12O40S4 ) crystal system is triclinic, with space group P1, a=14.2890(3), b=14.3427(3), c=20.1601(2)? =76.636(1), b=84.496(1), =60.316(1)? V=3491.4(1)?, Z=2, Mr =1861.02, Dc=1.770 g/cm3, m=1.608mm-1, F(000)=1856, the final R=0.0776 and wR=0.1724 for 8804 reflections with I > 2s(I).展开更多
To investigate physicochemical stability of sevofuranein dimethyl sulfoxide using gas chromatography with a fame ionization detector and nuclear magnetic reso-nance （NMR）.METHODSUndiluted sevoflurane, plus dilution...To investigate physicochemical stability of sevofuranein dimethyl sulfoxide using gas chromatography with a fame ionization detector and nuclear magnetic reso-nance （NMR）.METHODSUndiluted sevoflurane, plus dilutions 1：2, 1：5, 1：10, 1：25, and 1：50 in dimethyl sulfoxide were prepared in a vertical laminar fow cabinet class Ⅱ type B and stored at different temperatures （23 ℃, 6 ℃, and -10 ℃） for 45 d. Sterile 1 mL polypropylene amber syringes to minimize light degradation, caps and needles were used. The presence of sevofurane and its degradation products in the samples was determined by gas chroma-tography with flame ionization detector （260 ℃, 40min）, and by 1H, 19F, and proton-decoupled 19F nuclearmagnetic resonance.RESULTS The gas chromatography analysis showed sevofluraneand dimethyl sulfoxide （DMSO） retention times were 2.7and 13.0 min, respectively. Pure DMSO injection into thecolumn resulted in two additional peaks at 2.1 and 2.8min. The same sevofurane peak at 2.7 min was observedin all the dilutions at -10 ℃, 4 ℃ and 25 ℃. The NMRspectra showed signals consistent with the sevoflurane structure in all the dilutions at -10 ℃, 4 ℃ and 25 ℃. In the 1H spectrum, two signals corresponding to the sevoflurane molecule were observed at 5.12 and 4.16 parts per million （ppm5）. In the 19F-NMR spectrum, two signals were observed at -76.77 ppm and -157.13 ppm. In the 19F NMR CPD, two signals were observed at -76.77 ppm and -157.13 ppm. The first one showed a doublet （JF-F = 3.1 Hz） which integrated by six fluorine nuclei from the hexafluoro-isopropyl group. The second signal was integrated by a fuorine atom and showed a septuplet （JF-F = 3.1 Hz）.CONCLUSIONThis study shows that different concentrations ofsevofurane in dimethyl sulfoxide retain their chemicalcomposition after exposure to different temperaturesfor a period of 45 d.展开更多
BACKGROUND Matrix metalloproteinases(MMPs),including MMP-9,are an integral part of the immune response and are upregulated in response to a variety of stimuli.New details continue to emerge concerning the mechanistic ...BACKGROUND Matrix metalloproteinases(MMPs),including MMP-9,are an integral part of the immune response and are upregulated in response to a variety of stimuli.New details continue to emerge concerning the mechanistic and regulatory pathways that mediate MMP-9 secretion.There is significant evidence for regulation of inflammation by dimethyl sulfoxide(DMSO)and 3',5'-cyclic adenosine monophosphate(cAMP),thus investigation of how these two molecules may regulate both MMP-9 and tumor necrosis factorα(TNFα)secretion by human monocytes was of high interest.The hypothesis tested in this study was that DMSO and cAMP regulate MMP-9 and TNFαsecretion by distinct mechanisms.AIM To investigate the regulation of lipopolysaccharide(LPS)-stimulated MMP-9 and tumor necrosis factorαsecretion in THP-1 human monocytes by dimethyl sulfoxide and cAMP.METHODS The paper describes a basic research study using THP-1 human monocyte cells.All experiments were conducted at the University of Missouri-St.Louis in the Department of Chemistry and Biochemistry.Human monocyte cells were grown,cultured,and prepared for experiments in the University of Missouri-St.Louis Cell Culture Facility as per accepted guidelines.Cells were treated with LPS for selected exposure times and the conditioned medium was collected for analysis of MMP-9 and TNFαproduction.Inhibitors including DMSO,cAMP regulators,and anti-TNFαantibody were added to the cells prior to LPS treatment.MMP-9 secretion was analyzed by gel electrophoresis/western blot and quantitated by ImageJ software.TNFαsecretion was analyzed by enzyme-linked immuno sorbent assay.All data is presented as the average and standard error for at least 3 trials.Statistical analysis was done using a two-tailed paired Student t-test.P values less than 0.05 were considered significant and designated as such in the Figures.LPS and cAMP regulators were from Sigma-Aldrich,MMP-9 standard and antibody and TNFαantibodies were from R&D Systems,and amyloid-βpeptide was from rPeptide.RESULTS In our investigation of MMP-9 secretion from THP-1 human monocytes,we made the following findings.Inclusion of DMSO in the cell treatment inhibited LPSinduced MMP-9,but not TNFα,secretion.Inclusion of DMSO in the cell treatment at different concentrations inhibited LPS-induced MMP-9 secretion in a dosedependent fashion.A cell-permeable cAMP analog,dibutyryl cAMP,inhibited both LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the adenylyl cyclase activator forskolin inhibited LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the general cAMP phosphodiesterase inhibitor IBMX reduced LPS-induced MMP-9 and TNFαin a dose-dependent fashion.Pre-treatment of monocytes with an anti-TNFαantibody blocked LPSinduced MMP-9 and TNFαsecretion.Amyloid-βpeptide induced MMP-9 secretion,which occurred much later than TNFαsecretion.The latter two findings strongly suggested an upstream role for TNFαin mediating LPS-stimulate MMP-9 secretion.CONCLUSION The cumulative data indicated that MMP-9 secretion was a distinct process from TNFαsecretion and occurred downstream.First,DMSO inhibited MMP-9,but not TNFα,suggesting that the MMP-9 secretion process was selectively altered.Second,cAMP inhibited both MMP-9 and TNFαwith a similar potency,but at different monocyte cell exposure time points.The pattern of cAMP inhibition for these two molecules suggested that MMP-9 secretion lies downstream of TNFαand that TNFαmay a key component of the pathway leading to MMP-9 secretion.This temporal relationship fit a model whereby early TNFαsecretion directly led to later MMP-9 secretion.Lastly,antibody-blocking of TNFαdiminished MMP-9 secretion,suggesting a direct link between TNFαsecretion and MMP-9 secretion.展开更多
Highly substituted n-atkyl celluloses with sidechains 3 to 10 carbon atoms long have been prepared from cellulose acetate, sodium hydroxide and n-alkyl bromides with dimethyl sulfoxide as solvent. Synthetic conditions...Highly substituted n-atkyl celluloses with sidechains 3 to 10 carbon atoms long have been prepared from cellulose acetate, sodium hydroxide and n-alkyl bromides with dimethyl sulfoxide as solvent. Synthetic conditions of n-alkyl celluloses were studied with respect to reaction temperature, time and yield. The molecular structure of the n-alkyl celluloses, which were obtained as white powders or as sticky, soft and birefringent solids at room temperature, was investigated by IR and NMR spectra and elemental analysis. The highly substituted n-alkyl celluloses all exhibited both therotropic and lyotropic liquid crystalline cholesteric phases in some non-polar solvents. The metting behavior and solubility of the n-alkyl celluloses were examined.展开更多
基金partly supported by the National Key R&D Program of China(2022YFB4101602)the National Natural Science Foundation of China(22078052)the Fundamental Research Funds for the Central Universities(DUT22ZD207)。
文摘Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain for low-salt aqueous electrolytes operating at high voltage and low temperature.Herein,we report a low-salt(0.87 m,m means mol kg^(-1))'salt in dimethyl sulfoxide/water'hybrid electrolyte with non-flammability via hybridizing aqueous electrolyte with an organic co-solvent of dimethyl sulfoxide(hydrogen bond acceptor).As a result,the 0.87 m hybrid electrolyte exhibits enhanced electrochemical stability,a freezing temperature below-50℃,and an outstanding ionic conductivity of 0.52mS cm~(-1)at-50℃.Dimethyl sulfoxide can anchor water molecules through intermolecular hydrogen bond interaction,effectively reinforcing the stability of water in the hybrid electrolyte.Furthermore,the interaction between dimethyl sulfoxide and water molecules diminishes the involvement of water in the generation of ordered ice crystals,finally facilitating the low-temperature performance of the hybrid electrolyte.When paired with the 0.87 m'salt in dimethyl sulfoxide/water'hybrid electrolyte,the symmetric supercapacitor presents a 2.0 V high operating voltage at 25℃,and can operate stably at-50℃.Importantly,the suppressed electrochemical reaction of water at-50℃further leads to the symmetric supercapacitor operated at a higher voltage of 2.6 V.This modification strategy opens an effective avenue to develop low-salt electrolytes for high-voltage and low-temperature aqueous supercapacitors.
基金Supported by National 11th Five-Year Plan of China for Military Medical Projects,No.06Z055the National Natural Science Foundation of China,No.81301607
文摘AIM: To investigate whether dimethyl sulfoxide(DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatoryresponse syndrome and multiple organ dysfunction syndrome.METHODS: Sprague-Dawley rats were randomly divided into four groups: sham with administration of normal saline(SS group); sham with administration of DMSO(SD group); zymosan with administration of normal saline(ZS group); and zymosan with administration of DMSO(ZD group). Each group contained three subgroups according to 4 h,8 h,and 24 h after surgery. At 4 h,8 h,and 24 h after intraperitoneal injection of zymosan(750 mg/kg),the levels of intestinal inflammatory cytokines [tumor necrosis factor-alpha(TNF-α) and interleukin(IL)-10] and oxides(myeloperoxidase,malonaldehyde,and superoxide dismutase) were examined. The levels of diamine oxidase(DAO) in plasma and intestinal mucosal blood flow(IMBF) were determined. Intestinal injury was also evaluated using an intestinal histological score and apoptosis of intestinal epithelial cells was determined by deoxynucleotidyl transferase d UTP nick end labeling(TUNEL) assay. The intestinal epithelial tight junction protein,ZO-1,was observed by immunofluorescence.RESULTS: DMSO decreased TNF-α and increased IL-10 levels in the intestine compared with the ZS group at the corresponding time points. The activity of intestinal myeloperoxidase in the ZS group was higher than that in the ZD group 24 h after zymosan administration(P < 0.05). DMSO decreased the content of malondialdehyde(MDA) and increased the activity of superoxide dehydrogenase(SOD) 24 h after zymosan administration. The IMBF was lowest at 24 h and was 49.34% and 58.26% in the ZS group and ZD group,respectively(P < 0.05). DMSO alleviated injury in intestinal villi,and the gut injury score was significantly lower than the ZS group(3.6 ± 0.2 vs 4.2 ± 0.3,P < 0.05). DMSO decreased the level of DAO in plasma compared with the ZS group(65.1 ± 4.7 U/L vs 81.1 ± 5.0 U/L,P < 0.05). DMSO significantly preserved ZO-1 protein expression and localization 24 h after zymosan administration. The TUNEL analysis indicated that the number of apoptotic intestinal cells in the ZS group was much higher than the ZD group(P < 0.05).CONCLUSION: DMSO inhibited intestinal cytokines and protected against zymosan-induced gut barrier dysfunction.
基金supported by the Natural Science Foundation of Inner Mongolia Autonomous Region (2016JQ02)the Program for Grassland Excellent Talents of Inner Mongolia Autonomous Region, Program for New Century Excellent Talents in University (NCET-12-1017)training plan of academic backbone in youth of Inner Mongolia University of Technology
文摘The work presents density(ρ) and viscosity(η) data of binary system polyethylene glycol 600(PEG) + dimethyl sulfoxide(DMSO) over the entire concentration range at T =(298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. On the basis of density and viscosity values, the excess properties of PEG(1) + DMSO(2) mixtures, including excess molar volume(V_m^E), viscosity deviation(Δη), excess free energies of activation(ΔG^(*E)), and isobaric thermal expansion coefficient(αp), were calculated. At the same time, in order to conjecture the density viscosity under different conditions, the density and viscosity data were fitted with the corresponding formula. The calculated results of V_m^E, Δη, and ΔG^(*E) were fitted with the Redlich–Kister equation to derive coefficients and estimate the standard deviations(σ) between the experimental and calculated values. Moreover, the intermolecular interaction of PEG with DMSO was discussed on the basis of FTIR and UV–Vis spectral results of PEG(1) + DMSO(2) mixtures. The results indicated that there were the hydrogen bonding and interactions of hydroxyl hydrogen atoms in PEG with oxygen atoms in DMSO.
文摘A novel one-dimensional chain complex [Pr2(bnbo)6(DMSO)4] (bnbo=3,5-binitro benzoyloxy, DMSO= dimethyl sulfoxide) with bridging carboxyl groups was synthesized and its structure has been determined by single-crystal X-ray methods. In the complex, a pair of adjacent metal ions are alternately connected by four or two carboxylate groups to form an infinite chain of 8-coordinated Pr3+ ions. The complex (Pr2C50H42N12O40S4 ) crystal system is triclinic, with space group P1, a=14.2890(3), b=14.3427(3), c=20.1601(2)? =76.636(1), b=84.496(1), =60.316(1)? V=3491.4(1)?, Z=2, Mr =1861.02, Dc=1.770 g/cm3, m=1.608mm-1, F(000)=1856, the final R=0.0776 and wR=0.1724 for 8804 reflections with I > 2s(I).
文摘To investigate physicochemical stability of sevofuranein dimethyl sulfoxide using gas chromatography with a fame ionization detector and nuclear magnetic reso-nance （NMR）.METHODSUndiluted sevoflurane, plus dilutions 1：2, 1：5, 1：10, 1：25, and 1：50 in dimethyl sulfoxide were prepared in a vertical laminar fow cabinet class Ⅱ type B and stored at different temperatures （23 ℃, 6 ℃, and -10 ℃） for 45 d. Sterile 1 mL polypropylene amber syringes to minimize light degradation, caps and needles were used. The presence of sevofurane and its degradation products in the samples was determined by gas chroma-tography with flame ionization detector （260 ℃, 40min）, and by 1H, 19F, and proton-decoupled 19F nuclearmagnetic resonance.RESULTS The gas chromatography analysis showed sevofluraneand dimethyl sulfoxide （DMSO） retention times were 2.7and 13.0 min, respectively. Pure DMSO injection into thecolumn resulted in two additional peaks at 2.1 and 2.8min. The same sevofurane peak at 2.7 min was observedin all the dilutions at -10 ℃, 4 ℃ and 25 ℃. The NMRspectra showed signals consistent with the sevoflurane structure in all the dilutions at -10 ℃, 4 ℃ and 25 ℃. In the 1H spectrum, two signals corresponding to the sevoflurane molecule were observed at 5.12 and 4.16 parts per million （ppm5）. In the 19F-NMR spectrum, two signals were observed at -76.77 ppm and -157.13 ppm. In the 19F NMR CPD, two signals were observed at -76.77 ppm and -157.13 ppm. The first one showed a doublet （JF-F = 3.1 Hz） which integrated by six fluorine nuclei from the hexafluoro-isopropyl group. The second signal was integrated by a fuorine atom and showed a septuplet （JF-F = 3.1 Hz）.CONCLUSIONThis study shows that different concentrations ofsevofurane in dimethyl sulfoxide retain their chemicalcomposition after exposure to different temperaturesfor a period of 45 d.
基金Supported by The University of Missouri-St.Louis,Alzheimer’s Association,No.NIRG-06-27267the Missouri Alzheimer’s and Related Disorders Research Program.
文摘BACKGROUND Matrix metalloproteinases(MMPs),including MMP-9,are an integral part of the immune response and are upregulated in response to a variety of stimuli.New details continue to emerge concerning the mechanistic and regulatory pathways that mediate MMP-9 secretion.There is significant evidence for regulation of inflammation by dimethyl sulfoxide(DMSO)and 3',5'-cyclic adenosine monophosphate(cAMP),thus investigation of how these two molecules may regulate both MMP-9 and tumor necrosis factorα(TNFα)secretion by human monocytes was of high interest.The hypothesis tested in this study was that DMSO and cAMP regulate MMP-9 and TNFαsecretion by distinct mechanisms.AIM To investigate the regulation of lipopolysaccharide(LPS)-stimulated MMP-9 and tumor necrosis factorαsecretion in THP-1 human monocytes by dimethyl sulfoxide and cAMP.METHODS The paper describes a basic research study using THP-1 human monocyte cells.All experiments were conducted at the University of Missouri-St.Louis in the Department of Chemistry and Biochemistry.Human monocyte cells were grown,cultured,and prepared for experiments in the University of Missouri-St.Louis Cell Culture Facility as per accepted guidelines.Cells were treated with LPS for selected exposure times and the conditioned medium was collected for analysis of MMP-9 and TNFαproduction.Inhibitors including DMSO,cAMP regulators,and anti-TNFαantibody were added to the cells prior to LPS treatment.MMP-9 secretion was analyzed by gel electrophoresis/western blot and quantitated by ImageJ software.TNFαsecretion was analyzed by enzyme-linked immuno sorbent assay.All data is presented as the average and standard error for at least 3 trials.Statistical analysis was done using a two-tailed paired Student t-test.P values less than 0.05 were considered significant and designated as such in the Figures.LPS and cAMP regulators were from Sigma-Aldrich,MMP-9 standard and antibody and TNFαantibodies were from R&D Systems,and amyloid-βpeptide was from rPeptide.RESULTS In our investigation of MMP-9 secretion from THP-1 human monocytes,we made the following findings.Inclusion of DMSO in the cell treatment inhibited LPSinduced MMP-9,but not TNFα,secretion.Inclusion of DMSO in the cell treatment at different concentrations inhibited LPS-induced MMP-9 secretion in a dosedependent fashion.A cell-permeable cAMP analog,dibutyryl cAMP,inhibited both LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the adenylyl cyclase activator forskolin inhibited LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the general cAMP phosphodiesterase inhibitor IBMX reduced LPS-induced MMP-9 and TNFαin a dose-dependent fashion.Pre-treatment of monocytes with an anti-TNFαantibody blocked LPSinduced MMP-9 and TNFαsecretion.Amyloid-βpeptide induced MMP-9 secretion,which occurred much later than TNFαsecretion.The latter two findings strongly suggested an upstream role for TNFαin mediating LPS-stimulate MMP-9 secretion.CONCLUSION The cumulative data indicated that MMP-9 secretion was a distinct process from TNFαsecretion and occurred downstream.First,DMSO inhibited MMP-9,but not TNFα,suggesting that the MMP-9 secretion process was selectively altered.Second,cAMP inhibited both MMP-9 and TNFαwith a similar potency,but at different monocyte cell exposure time points.The pattern of cAMP inhibition for these two molecules suggested that MMP-9 secretion lies downstream of TNFαand that TNFαmay a key component of the pathway leading to MMP-9 secretion.This temporal relationship fit a model whereby early TNFαsecretion directly led to later MMP-9 secretion.Lastly,antibody-blocking of TNFαdiminished MMP-9 secretion,suggesting a direct link between TNFαsecretion and MMP-9 secretion.
文摘Highly substituted n-atkyl celluloses with sidechains 3 to 10 carbon atoms long have been prepared from cellulose acetate, sodium hydroxide and n-alkyl bromides with dimethyl sulfoxide as solvent. Synthetic conditions of n-alkyl celluloses were studied with respect to reaction temperature, time and yield. The molecular structure of the n-alkyl celluloses, which were obtained as white powders or as sticky, soft and birefringent solids at room temperature, was investigated by IR and NMR spectra and elemental analysis. The highly substituted n-alkyl celluloses all exhibited both therotropic and lyotropic liquid crystalline cholesteric phases in some non-polar solvents. The metting behavior and solubility of the n-alkyl celluloses were examined.
