The electrooxidation behavior of 3, 3′,5, 5′-tetramethylbenzidine(TMB) was investigated using a platinum minigrid optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electroo...The electrooxidation behavior of 3, 3′,5, 5′-tetramethylbenzidine(TMB) was investigated using a platinum minigrid optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electrooxidation process to yield quinonediimine in the pH range from 2.0 to < 4.0, and two consecutive one-electron electrooxidation processes, gave the mediate product free radical of TMB first, then gave the oxidation product quinonediimine in the pH range from 4.0 to < 7.0. In the pH range from 7.0 to 10.0, the electrooxidation of TMB was also one two-electron electrooxidation process to yield an azo compound. The formal potential E0'and the electron transfer number of the electrooxidation of TMB at pH 2.0 and pH 8.4 were determined by spectroelectrochemical techniques.展开更多
The CoCr/Pt bilayers and (CoCr/Pt)_(20) multilayers with Pt underlayer wereprepared by DC magnetron sputtering. The effects of prepared condition on perpendicular magneticanisotropy were investigated. The results show...The CoCr/Pt bilayers and (CoCr/Pt)_(20) multilayers with Pt underlayer wereprepared by DC magnetron sputtering. The effects of prepared condition on perpendicular magneticanisotropy were investigated. The results show that the thickness of Pt under-layer has a greateffect on the microstructure and perpendicular magnetic anisotropy of CoCr/Pt bilayers and(CoCr/Pt)_(20) multilayers. When the thickness of Pt underlayer increases, Pt(lll) and CoCr(002)peaks of both CoCr/Pt bilayers and (CoCr/Pt)_(20) multilayers increase and the bilayer periodicityof the multilayers is improved. The effective magnetic anisotropy of (CoCr/Pt)_(20) multilayers withPt underlayer was much larger than that of CoCr/Pt bilayers. The (CoCr/Pt)_(20) multilayers has astronger perpendicular magnetic anisotropy than that of CoCr/Pt bilayers. This is ascribed to theinterface magnetic anisotropy of the multilayers.展开更多
Background:The development of severe coronavirus disease 2019(COVID-19)is associated with systemic hyperinflammation,which drives multi-organ failure and death.Disease deterioration tends to occur when the virus is re...Background:The development of severe coronavirus disease 2019(COVID-19)is associated with systemic hyperinflammation,which drives multi-organ failure and death.Disease deterioration tends to occur when the virus is receding;however,whether other factors besides viral products are involved in the inflammatory cascade remains unclear.Methods:Twenty-eight COVID-19 patients with laboratory-confirmed SARS-CoV-2 infection hospitalized at the Fifth Medical Center of Chinese PLA General Hospital from January 23 to February 20,2020 and nine healthy donors during the same period were recruited in the study.COVID-19 patients were grouped as mild,moderate,severe based on disease severity.Plasma damage-associated molecular patterns(DAMPs),including high mobility group box 1(HMGB1),calprotectin(S100A8/A9),surfactant protein A(SP-A),cold-inducible RNA-binding protein(CIRBP),and Histone H4 were detected by ELISA assay,and analyzed in combination with clinical data.Plasma cytokines,chemokines and lymphocytes were determined by flow cytometry.Results:Plasma levels of HMGB1(38292.3±4564.4 vs.32686.3±3678.1,P=0.002),S100A8/A9(1490.8±819.3 vs.742.2±300.8,P=0.015),and SP-A(6713.6±1708.7 vs.5296.3±1240.4,P=0.048)were increased in COVID-19 patients compared to healthy donors,while CIRBP(57.4±30.7 vs.111.9±55.2,P=0.004)levels decreased.Five DAMPs did not vary among mild,moderate,and severe patients.Moreover,SP-A levels correlated positively with inflammatory cytokines and negatively with time elapsed after symptom onset,whereas CIRBP showed an opposite pattern.Conclusions:These findings suggest SP-A may involve in the inflammation of COVID-19,while CIRBP likely plays a protective role.Therefore,DAMPs represent a potential target in the prevention or treatment of COVID-19.展开更多
基金The project was supported by the National Natural Science Foundation of China(Grant No.20075013).
文摘The electrooxidation behavior of 3, 3′,5, 5′-tetramethylbenzidine(TMB) was investigated using a platinum minigrid optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electrooxidation process to yield quinonediimine in the pH range from 2.0 to < 4.0, and two consecutive one-electron electrooxidation processes, gave the mediate product free radical of TMB first, then gave the oxidation product quinonediimine in the pH range from 4.0 to < 7.0. In the pH range from 7.0 to 10.0, the electrooxidation of TMB was also one two-electron electrooxidation process to yield an azo compound. The formal potential E0'and the electron transfer number of the electrooxidation of TMB at pH 2.0 and pH 8.4 were determined by spectroelectrochemical techniques.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50301002) and the New Star Plan of Science and Technology of Beijing (No.H020821290120)
文摘The CoCr/Pt bilayers and (CoCr/Pt)_(20) multilayers with Pt underlayer wereprepared by DC magnetron sputtering. The effects of prepared condition on perpendicular magneticanisotropy were investigated. The results show that the thickness of Pt under-layer has a greateffect on the microstructure and perpendicular magnetic anisotropy of CoCr/Pt bilayers and(CoCr/Pt)_(20) multilayers. When the thickness of Pt underlayer increases, Pt(lll) and CoCr(002)peaks of both CoCr/Pt bilayers and (CoCr/Pt)_(20) multilayers increase and the bilayer periodicityof the multilayers is improved. The effective magnetic anisotropy of (CoCr/Pt)_(20) multilayers withPt underlayer was much larger than that of CoCr/Pt bilayers. The (CoCr/Pt)_(20) multilayers has astronger perpendicular magnetic anisotropy than that of CoCr/Pt bilayers. This is ascribed to theinterface magnetic anisotropy of the multilayers.
基金This work was supported by the Innovation Groups of the National Natural Science Foundation of China(No.81721002)the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2017ZX10202102-004-002)。
文摘Background:The development of severe coronavirus disease 2019(COVID-19)is associated with systemic hyperinflammation,which drives multi-organ failure and death.Disease deterioration tends to occur when the virus is receding;however,whether other factors besides viral products are involved in the inflammatory cascade remains unclear.Methods:Twenty-eight COVID-19 patients with laboratory-confirmed SARS-CoV-2 infection hospitalized at the Fifth Medical Center of Chinese PLA General Hospital from January 23 to February 20,2020 and nine healthy donors during the same period were recruited in the study.COVID-19 patients were grouped as mild,moderate,severe based on disease severity.Plasma damage-associated molecular patterns(DAMPs),including high mobility group box 1(HMGB1),calprotectin(S100A8/A9),surfactant protein A(SP-A),cold-inducible RNA-binding protein(CIRBP),and Histone H4 were detected by ELISA assay,and analyzed in combination with clinical data.Plasma cytokines,chemokines and lymphocytes were determined by flow cytometry.Results:Plasma levels of HMGB1(38292.3±4564.4 vs.32686.3±3678.1,P=0.002),S100A8/A9(1490.8±819.3 vs.742.2±300.8,P=0.015),and SP-A(6713.6±1708.7 vs.5296.3±1240.4,P=0.048)were increased in COVID-19 patients compared to healthy donors,while CIRBP(57.4±30.7 vs.111.9±55.2,P=0.004)levels decreased.Five DAMPs did not vary among mild,moderate,and severe patients.Moreover,SP-A levels correlated positively with inflammatory cytokines and negatively with time elapsed after symptom onset,whereas CIRBP showed an opposite pattern.Conclusions:These findings suggest SP-A may involve in the inflammation of COVID-19,while CIRBP likely plays a protective role.Therefore,DAMPs represent a potential target in the prevention or treatment of COVID-19.
