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8篇 您的检索式:作者名="Kexin Tan"
    题名 作者 年代 出处 被引量
1Soil aggregate fraction-based ^(14)C analysis and its application in the study of soil organic carbon turnover under forests of different ages显示文摘There still exist uncertainties in the trend, magnitude and efficiency of carbon sequestration with regard to the changes in soil organic carbon (SOC) pools after afforestation. In this study, SOC turnover times of the meadow steppe and planted forests at Saihanba Forest Station of Hebei Province, China are estimated by means of the radiocarbon ( 14C) method. Our results show that the SOC turnover times can be as long as from 70 to 250 years. After planting the Pinus sylvestri var. mongolica in the Leymus chinensis meadow steppe, the turnover times of organic carbon in both bulk samples and soil aggregate fractions of the topsoils are decreased with an increase of the stand age. Such a lowering of the turnover time would cause an increase in soil CO2 flux, implying that afforestation of grassland may reduce the capacity of topsoil to sequestrate organic carbon. Combined stable isotope and 14C analyses on soil aggregate fractions suggest that there are different responses to afforestation of grassland between young and old carbon pools in topsoils. In the young and middle-age planted forests, the proportion of CO 2 emission from the older soil carbon pool shows an increasing trend. But in the mature planted forest, its proportion tends to decline, indicating that the stand age may influence the soil carbon sequestration mechanism. The CO2 emission from the topsoils estimated using the 14 C method is relatively low compared to those by other methods and may be caused by the partial isolation of the young carbon component from the soil aggregates. For more accurate estimation of CO2 flux, future studies should therefore employ improved methodology for more effective separation of different soil carbon components before isotope analyses.TAN WenBing ZHOU LiPing LIU KeXin 2013Chinese Science Bulletin2013,58,16:3
2Organic anion transporters also mediate the drug–drug interaction between imipenem and cilastatin显示文摘This study aimed to clarify that organic anion transporters(OATs)mediate the drug–drug interaction(DDI)between imipenem and cilastatin.After co-administration with imipenem,the plasma concentrations and the plasma concentration-time curve(AUC)of cilastatin were significantly increased,while renal clearance and cumulative urinary excretion of cilastatin were decreased.At the same time,imipenem significantly inhibited the uptake of cilastatin in rat kidney slices and in human OAT1(hOAT1)-HEK293 and human OAT3(hOAT3)-HEK293 cells.Probenecid,p-aminohippurate,and benzylpenicillin inhibited the uptake of imipenem and cilastatin in rat kidney slices and in hOAT1-and hOAT3-HEK 293 cells,respectively.The uptakes of imipenem and cilastatin in hOAT1-and hOAT3-HEK 293 cells were significantly higher than that in mock-HEK-293 cells.Moreover,the K m values of cilastatin were increased in the presence of imipenem with unchanged V max,indicating that imipenem inhibited the uptake of cilastatin in a competitive manner.When imipenem and cilastatin were co-administered,the level of imipenem was higher compared with imipenem alone both in vivo and in vitro.But,cilastatin significantly inhibited the uptake of imipenem when dehydropeptidase-1(DPEP1)was silenced by RNAi technology in hOAT1-and hOAT3-HEK 293 cells.In conclusion,imipenem and cilastatin are the substrates of OAT1 and OAT3.OAT1 and OAT3 mediate the DDI between imipenem and cilastatin.Meanwhile,cilastatin also reduces the hydrolysis of imipenem by inhibiting the uptake of imipenem mediated by OAT1 and OAT3 in the kidney as a complement.Yanna Zhu Xiaokui Huo Changyuan Wang Qiang Meng Zhihao Liu Huijun Sun Aiping Tan Xiaodong Ma Jinyong Peng Kexin Liu 2020Asian Journal of Pharmaceutical Sciences2020,15,2:3
3Anti-arthritic effects of microneedling with bee venom gel显示文摘Objective:To combine with transdermal drug delivery using microneedle to simulate the bee venom therapy to evaluate the permeation of bee venom gel.Methods:In this study,the sodium urate and LPS were used on rats and mice to construct the model.Bee venom gelemicroneedle combination effect on the model is to determine the role of microneedle gel permeation by observing inflammation factors.Results:Compared with the model group,the bee venom gelemicroneedle combination group can reduce the level of serum nitric oxide of the acute gouty inflammation model caused by sodium urate,and on LPS induced mouse model of acute inflammation effect and the micro.Conclusions:Bee venom can significantly suppress the occurrence of gouty arthritis inflammation in rats and mice LPS inflammatory reaction.Choose the 750 mm microneedle with 10N force on skin about 3 minutes,bee venom can play the optimal role,and the anti-inflammatory effect is obvious.Microneedles can promote the percutaneous absorption of the active macromolecules bee venom gel.Mengdi Zhao Jie Bai Yang Lu Shouying Du Kexin Shang Pengyue Li Liu Yang Boyu Dong Ning Tan 2016Journal of Traditional Chinese Medical Sciences2016,3,4:2
4A binder-free CF|PANI composite electrode with excellent capacitance for asymmetric supercapacitors显示文摘In this work,carbon fiber and polyaniline(CF|PANI)composites are prepared by using an electrochemical polymeriza-tion method.The morphology and composition characterization results show that the PANI nanospheres are successfully syn-thesized and uniformly coated on the CF.When the electrodeposition period is 300 cycles,the as-prepared CF|PANI electrode ex-hibits good specific capacitance of 231.63 F/g at 1 A/g,high performance of 98.14%retention rate from 0.5 to 20 A/g,and excel-lent cycle stability with only 0.96%capacity loss after 1000 cycles.This is ascribed to the internal resistance that was signific-antly reduced without binders,which helps to the CF|PANI electrode maintains high operating potential and pseudo-capacit-ance performance at high current density.The symmetrical supercapacitor based on two CF|PANI electrodes connecting by acid-ic PVA-H2SO4 gel electrolyte exhibits an energy density of 6.55 W·h/kg at a power density of 564.37 W/kg.In addition,the asym-metric supercapacitor based on MoS2|MWCNTs and CF|PANI electrodes with neutral PVA-Na2SO4 gel electrolyte shows an en-ergy density of 16.12 W·h/kg at a power density of 525.03 W/kg.These results indicate that the low internal resistance contrib-utes to the high energy density of symmetrical supercapacitors and asymmetric supercapacitors at high current density and high power density,which is significant for its practical application.Kexin Li Gentian Yue Furui Tan 2023Journal of Semiconductors2023,44,3:1
5Bifunctional interstitial phosphorous doping strategy boosts platinum-zinc alloy for efficient ammonia oxidation reaction and hydrogen evolution reaction显示文摘It is still a lack of bifunctional catalysts for ammonia oxidation reaction(AOR)and hydrogen evolution reaction(HER)due to their different reaction mechanisms.In this work,P is doped into PtZn alloy by calcination with NaH_(2)PO_(2) as P source to induce the lattice tensile strain of Pt and the electronic interaction between P and Zn,which optimizes the AOR and HER activity simultaneously.The sample with the optimal P content can drive the AOR peak current density of 293.6 mA·mgPt^(-1),which is almost 2.7 times of Pt.For HER,the overpotential at^(-1)0 mA·cm^(-2) is only 23 mV with Tafel slope of 34.1 mV·dec^(-1).Furthermore,only 0.59 V is needed to obtain 50 mA·mgPt^(-1) for ammonia electrolysis under a two-electrode system.Therefore,this work shows an ingenious method to design bifunctional catalysts for ammonia electrolysis.Tianqi Yu Kexin Tan Jia Wu Yongjin Zou Shibin Yin 2024Nano Research2024,17,3:0
6Strong electronic coupling of CoNi and N-doped-carbon for efficient urea-assisted H2 production at a large current density显示文摘Exploiting efficient urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)catalysts are significant for energy-saving H2 production through urea-assisted water electrolysis,but it is still challenging.Herein,carbon-encapsulated CoNi coupled with CoNiMoO(CoNi@CN-CoNiMoO)is prepared by solvothermal method and calcination to enhance the activity/stability of urea-assisted water electrolysis at large current density.It exhibits good activity for UOR(E10/1,000=1.29/1.40 V)and HER(E-10/-1000=-45/-245 mV)in 1.0 M KOH+0.5 M urea solution.For the UOR||HER system,CoNi@CN-CoNiMoO only needs 1.58 V at 500 mA cm-2 and shows good stability.Density functional theory calculation suggests that the strong electronic interaction at the interface between NiCo alloy and N-doping-carbon layers can optimize the adsorption/desorption energy of UOR/HER intermediates and accelerate the water dissociation,which can expedite urea decomposition and Volmer step,thus increasing the UOR and HER activity,respectively.This work provides a new solution to design UOR/HER catalysts for H2 production through urea-assisted water electrolysis.Guangfu Qian Jinli Chen Wenjie Jiang Tianqi Yu Kexin Tan Shibin Yin 2023Carbon Energy2023,5,12:0
7Effect of Microstructural Characteristics on Fracture Toughness in Direct Energy Deposited Novel Ti-6Al-4V-1Mo Alloy显示文摘Meeting the damage tolerance requirements for engineering-grade titanium alloys pose a significant challenge in achieving high fracture toughness in direct energy deposition(DED)titanium alloys.This work primarily investigated the relationship between the microstructure and the fracture toughness of DED new Ti-6Al-4V-1Mo alloy.Two types of microstructures were designed via two process strategies:high-line energy density(HE)and low-line energy density(LE).Relative to LE samples,HE samples possess larger-sized microstructural characteristics(coarser grain boundaryα(α_(GB)),largerαcolonies,and coarserαlaths).Lessα/βphase boundaries were formed by coarserαlaths in the HE samples,increasing the movement of dislocations,resulting in tensile strength decreasing from 1007.1 MPa(LE)to 930.8 MPa(HE)and elongation increasing from 10.8%(LE)to 15.7%(HE).Also,HE samples exhibited an excellent fracture toughness of 114.0 MPa m^(1/2),significantly higher than that of LE samples(76.8 MPa m^(1/2)).An analysis of crack propagation paths was conducted to investigate the factors contributing to toughening.The primary factor enhancing toughness is the frequent obstruction of cracks by coarseαGB and largeαcolonies in HE samples.Particularly,the pretty large-angle deflections induced by the superposition effect of coarseαGB and largeαcolonies play a vital of significant role.These factors induced the long and tortuous high-energy pathways,which resulted in ultimately improved fracture toughness.The discovered microstructural toughening mechanisms can serve as a reference for future studies involving titanium alloys,offering insights on how to enhance fracture toughness by achieving similar characteristics.Chao Xia Kexin Zhao Xin Zhou Yuqi He Panpan Gao Hengxin Zhang Guangrui Gao Fengying Zhang Hua Tan 2024Acta Metallurgica Sinica(English Letters)2024,37,1:0
8Ectopic expression of AANAT or HIOMT improves melatonin production and enhances UV-B tolerance in transgenic apple plants显示文摘Melatonin is involved in plant responses to various environmental stresses.Although many studies have demonstrated that the tolerance of plants to stress is improved by exogenous melatonin,the role of endogenous melatonin metabolism in the response of apples to UV-B stress remains unclear.Here,the human melatonin biosynthesis-related enzyme genes AANAT or HIOMT were transformed into‘GL-3'apple,and the transgenic lines were treated with UV-B stress.The ectopic expression of AANAT or HIOMT significantly increased the melatonin content in apples.After UV-B stress,the tolerance of apple lines with ectopic expression of AANAT or HIOMT was markedly improved.The decrease in chlorophyll fluorescence,the generation of reactive oxygen species and the shrinkage of stomata caused by UV-B stress were alleviated by AANAT or HIOMT ectopic expression.In addition,the total phenolic content was markedly increased in the transgenic lines compared with the WT(wild type).The increase in phenolic compounds was related to the increase in benzoic acid,hydroxycinnamic acid,dihydrochalcones and flavanols,among which increases in chlorogenic acid,phloridzin and procyanidin B1 content were most prominent.Furthermore,the transgenic lines did not only promote the expression of genes related to phenolic synthesis under UV-B stress,but they also increased the accumulation of phenolic compounds by inhibiting the expression of MdPPO and MdPOD related to phenolic degradation.In summary,our results demonstrate that AANAT-or HIOMT-mediated melatonin synthesis improved the tolerance of apples to UV-B stress,mainly by scavenging reactive oxygen species,increasing photosynthetic capacity and increasing total phenolic content.Xiaomin Liu Zhiwei Wei Tengteng Gao Zhijun Zhang Kexin Tan Chao Li Fengwang Ma 2021Fruit Research2021,1,1:0
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