Oxygen-rich porous carbons are promising candidates for the carbon-based cathodes of zinc ion hybrid capacitors(ZIHCs).Potassium activation is a traditional and effective way to prepare oxygen-rich porous carbons.Effi...Oxygen-rich porous carbons are promising candidates for the carbon-based cathodes of zinc ion hybrid capacitors(ZIHCs).Potassium activation is a traditional and effective way to prepare oxygen-rich porous carbons.Efficient potassium activation is the key to develop high-performance oxygen-rich porous carbon cathodes.Herein,the alkali lignin,extracted from eucalyptus wood by geopolymer-assisted low-alkali pretreatment,is used to prepare oxygen-rich lignin-derived porous carbons(OLPCs)through KOH activation and K_(2)CO_(3)activation at 700-900℃.KOH activation constructs a hierarchical micro-mesoporous structure,while K_(2)CO_(3)activation constructs a microporous structure.Furthermore,K_(2)CO_(3)activation could more efficiently construct active oxygen(C=O)species than KOH activation.The OLPCs prepared by KOH/K_(2)CO_(3)activations at 800℃show the highest microporosity(78.4/87.7%)and C=O content(5.3/8.0 at.%).Due to that C=O and micropore adsorb zinc ions,the OLPCs prepared by K_(2)CO_(3)activation at 800℃with higher C=O content and microporosity deliver superior capacitive performance(256 F g^(-1)at 0.1 A g^(-1))than that by KOH activation at 800℃(224 F g^(-1)at 0.1 A g^(-1)),and excellent cycling stability.This work provides a new insight into the sustainable preparation of oxygenrich porous carbon cathodes through efficient potassium activation for ZIHCs.展开更多
A series of activated carbons from Taixi anthracite were prepared by steam activation in the presence of KOH and then they were modified by different methods. The regulation of porosity and the modification of surface...A series of activated carbons from Taixi anthracite were prepared by steam activation in the presence of KOH and then they were modified by different methods. The regulation of porosity and the modification of surface chemistry were carried out with the aim to improve the benzene adsorption capacity of activated carbon. The influences of KOH and activation process parameters including activation temperature, activation time and steam flow rate on porosity of activated carbon were evaluated, and the effect of modification methods on surface chemistry was investigated. Also, the relationship between benzene adsorption capacity and porosity and surface chemistry was analyzed. Results show that activation temperature is the dominant factor in the activation process; the introduction of KOH into the raw material can enhance the reactivity of char in activation process, meanwhile it shows a negative effect on the porosity development, especially on the mesopore development. Results of FTIR analysis indicate that anthracite-based activated carbon with condensed aromatics and chemically inert oxygen does not present the nature to be surface modified. Besides, benzene adsorption capacity has an approximate linear relationship with surface area and in our preparation, benzene adsorption capacity and surface area of activated carbon are up to 1210 m 2 /g and 423 mg/g, respectively.展开更多
Objective: To investigate changes of Ca2+ activated potassium channels (KCa) in autogenous vein grafts. Methods: Contraction of venous ring was measured by means of perfusion in vitro. The intimal rabbits proliferatio...Objective: To investigate changes of Ca2+ activated potassium channels (KCa) in autogenous vein grafts. Methods: Contraction of venous ring was measured by means of perfusion in vitro. The intimal rabbits proliferation of vascular and proliferation of cultured smooth muscle cells(vascular smooth muscle cells, VSMCs)were observed by the means of computerised image analysis and MTT method respectively. Furthermore, whole cell mode of patch clamp was used to record KCa of VSMCs isolated from autogenous vein grafts. Results: One week after transplantation there were no significant differences of contraction and intimal relative thickness between autogenous vein grafts and control. Contraction and intimal relative thickness of autogenous vein graft were significantly increased 2 weeks after transplantation (P<0.05, n=8 vs control), and they was more enhanced 4 weeks after vein transplantation (P<0.01, n=8 vs control).TEA(blocker of Ca2+ activated potassium channels)increased MTT A490 nm value of VSMCs from femoral vein in a dose dependent manner(P<0.05, n=8). KCa current density was significantly attenuated in VSMCs from autogenous vein grafts (1-4) week after transplantation(P<0.05, n=5).Conclusion: KCa is inhibited in autogenous vein graft, which account for vasospasm and intimal proliferation.展开更多
Highly active anhydrous potassium fluoride has many uses. Its good performance is demonstrated in high activity, high recovery, low consumption and the low emission of accessory substances during the process of organi...Highly active anhydrous potassium fluoride has many uses. Its good performance is demonstrated in high activity, high recovery, low consumption and the low emission of accessory substances during the process of organic fluorination. Moreover. there is no need to use an expensive intertransferable catalyst in the process of fluorination. Under the same conditions and within the same time limit, the fluorination rate of the product is 97% while that of ordinary anhydrous potassium fluoride is 58%. The product, developed recently by the Shenyang Chemical Research Institute, can remain in a state of superfine powder for a long time in air展开更多
The microcosmic reaction mechanism of the thermal decomposition of potassium nitroformate（KNF） has been investigated by density functional theory within the generalized gradient approximation. The geometric structur...The microcosmic reaction mechanism of the thermal decomposition of potassium nitroformate（KNF） has been investigated by density functional theory within the generalized gradient approximation. The geometric structures of reactants, intermediates, transition states, and products are fully optimized. The frequency analysis approves the authenticity of intermediates and transition states. Our results show that there are four feasible reaction pathways. The main pathway of the reaction is KNF → B1 → TSB1 → B2 → TSB2 → B3 → TSB3 → B4 → KNO2 ＋ NO2 ＋ NO ＋ CO, and the energy barrier of the rate-limiting step is 216.30 k J·mol^-1. The dominant products predicted theoretically are KNO2, NO2, NO, and CO, which is in agreement with the experiment.展开更多
Objectives To evaluate the association between a KCNQ 1 mutation, R259H, and short QT syndrome （SQTS） and to explore the elec- trophysiological mechanisms underlying their association. Methods We performed genetic s...Objectives To evaluate the association between a KCNQ 1 mutation, R259H, and short QT syndrome （SQTS） and to explore the elec- trophysiological mechanisms underlying their association. Methods We performed genetic screening of SQTS genes in 25 probands and their family members （63 patients）. We used direct sequencing to screen the exons and intron-exon boundaries of candidate genes that en- code ion channels which contribute to the repolarization of the ventricular action potential, including KCNQI, KCNH2, KCNE1, KCNE2, KCNJ2, CACNAlc, CACNB2b and CACNA2D1. In one of the 25 SQTS probands screened, we discovered a KCNQ1 mutation, R259H. We cloned R259H and transiently expressed it in HEK-293 cells; then, currents were recorded using whole cell patch clamp techniques. Results R259H-KCNQ 1 showed significantly increased current density, which was approximately 3-fold larger than that of wild type （WT） after a depolarizing pulse at 1 s. The steady state voltage dependence of the activation and inactivation did not show significant differences between the WT and R259H mutation （P 〉 0.05）, whereas the time constant of deactivation was markedly prolonged in the mutant compared with the WT in terms of the test potentials, which indicated that the deactivation of R259H was markedly slower than that of the WT. These results suggested that the R259H mutation can effectively increase the slowly activated delayed rectifier potassium current （Irs） in phase 3 of the cardiac action potential, which may be an infrequent cause of QT interval shortening. Conclusions R259H is a gain-of-function muta- tion of the KCNQ1 channel that is responsible for SQTS2. This is the first time that the R259H mutation was detected in Chinese people.展开更多
To investigate the effect of intedeukin-1β （IL-1β） on IA and IK currents in cultured murine trigeminal ganglion （TG） neurons, whole-cell patch clamp technique was used to record the IA and IK currents before and...To investigate the effect of intedeukin-1β （IL-1β） on IA and IK currents in cultured murine trigeminal ganglion （TG） neurons, whole-cell patch clamp technique was used to record the IA and IK currents before and after 20 ng/mL IL-1β perfusion. Our results showed that 20 ng/mL IL-1β inhibited IA currents （18.3±10.7）% （n=6, P〈0.05）. IL-1β at 20 ng/mL had no effect on G-V curve of IA but moved the H-infinity curve V0.5 from -36.6±6. 1 mV to-42.4±5.2 mV （n=5, P〈0.01）. However, 20 ng/mL IL-1β had effect on neither the amplitude nor the G-V curve of IK. IL-1β was found to selectively inhibit IA current in TG neurons and the effect may contribute to hyperalgesia under various inflammatory conditions.展开更多
Objective Abnormal QT prolongation associated with arrhythmias is considered the major cardiac electrical disorder and a significant predictor of mortality in diabetic patients. The precise ionic mechanisms for diabet...Objective Abnormal QT prolongation associated with arrhythmias is considered the major cardiac electrical disorder and a significant predictor of mortality in diabetic patients. The precise ionic mechanisms for diabetic QT prolongation remained unclear. The present study was designed to analyze the changes of ventricular repolarization and the underlying ionic mechanisms in diabetic rabbit hearts. Methods Diabetes was induced by a single injection ofalloxan （145mg/kg, Lv. ）. After the development of diabetes （10 weeks）, ECG was measured. Whole-cell patch-clamp technique was applied to record the action potential duration （APD50, APD90）, slowly activating outward rectifying potassium current （IKs）, L-type calcium current （ICa-L） and inward rectifying potassium current （IK1）. Results The action potential duration （APD50 and APD90） of ventricular myocytes was obviously prolonged from 271.5＋32.3 ms and 347.8＋36.3 ms to 556.6~72.5 ms and 647.9~72.2 ms respectively （P〈 0.05）. Meanwhile the normalized peak current densities of IKs in ventricular myocytes investigated by whole-cell patch clamp was smaller in diabetic rabbits than that in control group at test potential of＋50mV （1.27~0.20 pA/pF vs 3.08~0.67 pA/pF, P〈0.05）. And the density of the ICa-L was increased apparently at the test potential of 10 mV （-2.67~0.41 pA/pF vs -5.404-1.08 pA/pF, P〈0.05）. Conclusion Ventricular repolarization was prolonged in diabetic rabbits, it may be partly due to the increased L-type calcium current and reduced slow delayed rectifier K＋ current （IKs） （J Geriatr Cardio12010; 7：25-29）.展开更多
基金supported by the National Natural Science Foundation of China(22408061 and 22468005)Program for Introducing High-Level Talents from Guangxi University,and Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(2023Z014).
文摘Oxygen-rich porous carbons are promising candidates for the carbon-based cathodes of zinc ion hybrid capacitors(ZIHCs).Potassium activation is a traditional and effective way to prepare oxygen-rich porous carbons.Efficient potassium activation is the key to develop high-performance oxygen-rich porous carbon cathodes.Herein,the alkali lignin,extracted from eucalyptus wood by geopolymer-assisted low-alkali pretreatment,is used to prepare oxygen-rich lignin-derived porous carbons(OLPCs)through KOH activation and K_(2)CO_(3)activation at 700-900℃.KOH activation constructs a hierarchical micro-mesoporous structure,while K_(2)CO_(3)activation constructs a microporous structure.Furthermore,K_(2)CO_(3)activation could more efficiently construct active oxygen(C=O)species than KOH activation.The OLPCs prepared by KOH/K_(2)CO_(3)activations at 800℃show the highest microporosity(78.4/87.7%)and C=O content(5.3/8.0 at.%).Due to that C=O and micropore adsorb zinc ions,the OLPCs prepared by K_(2)CO_(3)activation at 800℃with higher C=O content and microporosity deliver superior capacitive performance(256 F g^(-1)at 0.1 A g^(-1))than that by KOH activation at 800℃(224 F g^(-1)at 0.1 A g^(-1)),and excellent cycling stability.This work provides a new insight into the sustainable preparation of oxygenrich porous carbon cathodes through efficient potassium activation for ZIHCs.
基金the financial support by the Special Fund for Basic Scientific Research of Central Colleges (No.2009KH10)the Beijing Postdoctoral Fund (No. B148)the Green Shoots Plan of Beijing Academy of Science and Technology of China (No. B142)
文摘A series of activated carbons from Taixi anthracite were prepared by steam activation in the presence of KOH and then they were modified by different methods. The regulation of porosity and the modification of surface chemistry were carried out with the aim to improve the benzene adsorption capacity of activated carbon. The influences of KOH and activation process parameters including activation temperature, activation time and steam flow rate on porosity of activated carbon were evaluated, and the effect of modification methods on surface chemistry was investigated. Also, the relationship between benzene adsorption capacity and porosity and surface chemistry was analyzed. Results show that activation temperature is the dominant factor in the activation process; the introduction of KOH into the raw material can enhance the reactivity of char in activation process, meanwhile it shows a negative effect on the porosity development, especially on the mesopore development. Results of FTIR analysis indicate that anthracite-based activated carbon with condensed aromatics and chemically inert oxygen does not present the nature to be surface modified. Besides, benzene adsorption capacity has an approximate linear relationship with surface area and in our preparation, benzene adsorption capacity and surface area of activated carbon are up to 1210 m 2 /g and 423 mg/g, respectively.
文摘Objective: To investigate changes of Ca2+ activated potassium channels (KCa) in autogenous vein grafts. Methods: Contraction of venous ring was measured by means of perfusion in vitro. The intimal rabbits proliferation of vascular and proliferation of cultured smooth muscle cells(vascular smooth muscle cells, VSMCs)were observed by the means of computerised image analysis and MTT method respectively. Furthermore, whole cell mode of patch clamp was used to record KCa of VSMCs isolated from autogenous vein grafts. Results: One week after transplantation there were no significant differences of contraction and intimal relative thickness between autogenous vein grafts and control. Contraction and intimal relative thickness of autogenous vein graft were significantly increased 2 weeks after transplantation (P<0.05, n=8 vs control), and they was more enhanced 4 weeks after vein transplantation (P<0.01, n=8 vs control).TEA(blocker of Ca2+ activated potassium channels)increased MTT A490 nm value of VSMCs from femoral vein in a dose dependent manner(P<0.05, n=8). KCa current density was significantly attenuated in VSMCs from autogenous vein grafts (1-4) week after transplantation(P<0.05, n=5).Conclusion: KCa is inhibited in autogenous vein graft, which account for vasospasm and intimal proliferation.
文摘Highly active anhydrous potassium fluoride has many uses. Its good performance is demonstrated in high activity, high recovery, low consumption and the low emission of accessory substances during the process of organic fluorination. Moreover. there is no need to use an expensive intertransferable catalyst in the process of fluorination. Under the same conditions and within the same time limit, the fluorination rate of the product is 97% while that of ordinary anhydrous potassium fluoride is 58%. The product, developed recently by the Shenyang Chemical Research Institute, can remain in a state of superfine powder for a long time in air
基金supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ131318,KJ1401227,KJ15012002)the Fuling Science and Technology Commission(FLKJ2015ABA1042)the Project of Chongqing Key Laboratory of Inorganic Special Functional Materials(KFKT201506)
文摘The microcosmic reaction mechanism of the thermal decomposition of potassium nitroformate（KNF） has been investigated by density functional theory within the generalized gradient approximation. The geometric structures of reactants, intermediates, transition states, and products are fully optimized. The frequency analysis approves the authenticity of intermediates and transition states. Our results show that there are four feasible reaction pathways. The main pathway of the reaction is KNF → B1 → TSB1 → B2 → TSB2 → B3 → TSB3 → B4 → KNO2 ＋ NO2 ＋ NO ＋ CO, and the energy barrier of the rate-limiting step is 216.30 k J·mol^-1. The dominant products predicted theoretically are KNO2, NO2, NO, and CO, which is in agreement with the experiment.
基金grants obtained from the National Natural Science Foundation of China （No.： 81170177, 81030002） and science and Technology De- partment of Gansu Province Project （145RJZ104）.
文摘Objectives To evaluate the association between a KCNQ 1 mutation, R259H, and short QT syndrome （SQTS） and to explore the elec- trophysiological mechanisms underlying their association. Methods We performed genetic screening of SQTS genes in 25 probands and their family members （63 patients）. We used direct sequencing to screen the exons and intron-exon boundaries of candidate genes that en- code ion channels which contribute to the repolarization of the ventricular action potential, including KCNQI, KCNH2, KCNE1, KCNE2, KCNJ2, CACNAlc, CACNB2b and CACNA2D1. In one of the 25 SQTS probands screened, we discovered a KCNQ1 mutation, R259H. We cloned R259H and transiently expressed it in HEK-293 cells; then, currents were recorded using whole cell patch clamp techniques. Results R259H-KCNQ 1 showed significantly increased current density, which was approximately 3-fold larger than that of wild type （WT） after a depolarizing pulse at 1 s. The steady state voltage dependence of the activation and inactivation did not show significant differences between the WT and R259H mutation （P 〉 0.05）, whereas the time constant of deactivation was markedly prolonged in the mutant compared with the WT in terms of the test potentials, which indicated that the deactivation of R259H was markedly slower than that of the WT. These results suggested that the R259H mutation can effectively increase the slowly activated delayed rectifier potassium current （Irs） in phase 3 of the cardiac action potential, which may be an infrequent cause of QT interval shortening. Conclusions R259H is a gain-of-function muta- tion of the KCNQ1 channel that is responsible for SQTS2. This is the first time that the R259H mutation was detected in Chinese people.
基金The project was supported by a grant from the National Natural Sciences Foundation of China (No. 30271500)
文摘To investigate the effect of intedeukin-1β （IL-1β） on IA and IK currents in cultured murine trigeminal ganglion （TG） neurons, whole-cell patch clamp technique was used to record the IA and IK currents before and after 20 ng/mL IL-1β perfusion. Our results showed that 20 ng/mL IL-1β inhibited IA currents （18.3±10.7）% （n=6, P〈0.05）. IL-1β at 20 ng/mL had no effect on G-V curve of IA but moved the H-infinity curve V0.5 from -36.6±6. 1 mV to-42.4±5.2 mV （n=5, P〈0.01）. However, 20 ng/mL IL-1β had effect on neither the amplitude nor the G-V curve of IK. IL-1β was found to selectively inhibit IA current in TG neurons and the effect may contribute to hyperalgesia under various inflammatory conditions.
基金This work was supported by the National Natural Science Foundation of China （30600253）, Min＆try of Edu- cation Key Project （207031） and Scientific Research Fundation for the Returned Chinese Scholars of Heilongjiang Province of China （LC07C20）.
文摘Objective Abnormal QT prolongation associated with arrhythmias is considered the major cardiac electrical disorder and a significant predictor of mortality in diabetic patients. The precise ionic mechanisms for diabetic QT prolongation remained unclear. The present study was designed to analyze the changes of ventricular repolarization and the underlying ionic mechanisms in diabetic rabbit hearts. Methods Diabetes was induced by a single injection ofalloxan （145mg/kg, Lv. ）. After the development of diabetes （10 weeks）, ECG was measured. Whole-cell patch-clamp technique was applied to record the action potential duration （APD50, APD90）, slowly activating outward rectifying potassium current （IKs）, L-type calcium current （ICa-L） and inward rectifying potassium current （IK1）. Results The action potential duration （APD50 and APD90） of ventricular myocytes was obviously prolonged from 271.5＋32.3 ms and 347.8＋36.3 ms to 556.6~72.5 ms and 647.9~72.2 ms respectively （P〈 0.05）. Meanwhile the normalized peak current densities of IKs in ventricular myocytes investigated by whole-cell patch clamp was smaller in diabetic rabbits than that in control group at test potential of＋50mV （1.27~0.20 pA/pF vs 3.08~0.67 pA/pF, P〈0.05）. And the density of the ICa-L was increased apparently at the test potential of 10 mV （-2.67~0.41 pA/pF vs -5.404-1.08 pA/pF, P〈0.05）. Conclusion Ventricular repolarization was prolonged in diabetic rabbits, it may be partly due to the increased L-type calcium current and reduced slow delayed rectifier K＋ current （IKs） （J Geriatr Cardio12010; 7：25-29）.
