Electrocatalytic water splitting provides an efficient method for the production of hydrogen.In electrocatalytic water splitting,the oxygen evolution reaction(OER)involves a kinetically sluggish four-electron transfer...Electrocatalytic water splitting provides an efficient method for the production of hydrogen.In electrocatalytic water splitting,the oxygen evolution reaction(OER)involves a kinetically sluggish four-electron transfer process,which limits the efficiency of electrocatalytic water splitting.Therefore,it is urgent to develop highly active OER catalysts to accelerate reaction kinetics.Coupling single atoms and clusters in one system is an innovative approach for developing efficient catalysts that can synergistically optimize the adsorption and configuration of intermediates and improve catalytic activity.However,research in this area is still scarce.Herein,we constructed a heterogeneous single-atom cluster system by anchoring Ir single atoms and Co clusters on the surface of Ni(OH)_(2)nanosheets.Ir single atoms and Co clusters synergistically improved the catalytic activity toward the OER.Specifically,Co_(n)Ir_(1)/Ni(OH)_(2)required an overpotential of 255 mV at a current density of 10 mA·cm^(−2),which was 60 mV and 67 mV lower than those of Co_(n)/Ni(OH)_(2)and Ir1/Ni(OH)_(2),respectively.The turnover frequency of Co_(n)Ir_(1)/Ni(OH)_(2)was 0.49 s^(−1),which was 4.9 times greater than that of Co_(n)/Ni(OH)_(2)at an overpotential of 300 mV.展开更多
OBJECTIVE Hepatocel ular carcinoma(HCC)is the most common cause of cancer-related mortality,with high incidence rates,robust metastatic propensity and acquired resistance to therapy.Metformin,an extensively prescribed...OBJECTIVE Hepatocel ular carcinoma(HCC)is the most common cause of cancer-related mortality,with high incidence rates,robust metastatic propensity and acquired resistance to therapy.Metformin,an extensively prescribed and well-tolerated first-linetherapeutic drug for type 2 diabetes mellitus,has recently been identified as a potential and attractive anticancer adjuvant drug combined with chemotherapeutics to improve treatment efficacy and lower doses.Curcumin,a botanical extracts,has been shown antitumorigenic properties.This study aims to investigate the combinational effect of metformin and curcumin on inbibition of tumor growth and metastasis in Hep G2 cells and the possible underlying mechanisms.METHODS The cell proliferation was determined by MTT,CCK-8 and colony formation assay.The protein expression was detected by Western blotting.Activity of MMP-2 and MMP-9 was estimated by gelatin zymography.Flow cytometry analysis was used to evaluate the influence of metformin and curcumin on cell cycle arrest and apoptosis,and morphology observation of apoptosis was detected by Hoechst33342.Scratch and transwell assay was performed to detect the cell migration and invasion.The suppression of this combination therapy oncapillary tube formation was detected by tube formation assay.RESULTS Combination of metformin and curcumin induced stronger inhibition on Hep G2 cells proliferation than monotherapywhich related to induction of cell cycle arrest in G2/M phase and apoptosis through regulation of the protein expression of cyclin B and Bcl-2/Bax.Moreover,the co-treatment of metformin with curcumin exerted an enhanced inhibitory effect on Hep G2 cell metastasis and synergistically inhibited the tube formation of HUVEC cells.The suppression of PI3K/AKT/m TOR pathway and inhibition the protein expression of STAT3,MMP9,MMP2 and VEGF might involve in this synergistic effects of combination treatment.CONCLUSION Combination of metformin and curcumin inhibited Hep G2 cells proliferationmore effectively than monotherapy and synergistically induced a greater inhibition on migration and invasion of Hep G2 cells.展开更多
In order to improve the anchoring force of anchors for carbon fiber reinforced polymer(CFRP) tendons further, a new wedge-bond-type anchor for CFRP tendons was developed. The increment in anchoring force induced by th...In order to improve the anchoring force of anchors for carbon fiber reinforced polymer(CFRP) tendons further, a new wedge-bond-type anchor for CFRP tendons was developed. The increment in anchoring force induced by the clamping segment of anchor was studied. Taking the deformation of all parts in clamping segment in the transverse direction into consideration, the calculation formula for the increment of anchoring force was proposed based on the linear elastic hypotheses. The proposed model is verified by experiments and conclusions are drawn that the anchoring force is influenced mainly by the inclination angle of clamping pieces, the length of clamping part and the thickness of bonding medium. Especially, the thickness of bonding medium should be lowered in design to improve the synergistic effect of anchors.展开更多
The synergistic inhibition effect of CeCl3(Ce)and serine(Ser)on the corrosion of carbon steel in a 3%NaCl solution was investigated by electrochemical methods and surface analysis.The results showed that both CeCl3 an...The synergistic inhibition effect of CeCl3(Ce)and serine(Ser)on the corrosion of carbon steel in a 3%NaCl solution was investigated by electrochemical methods and surface analysis.The results showed that both CeCl3 and Ser,when used alone,had limited inhibition effect toward carbon steel corrosion in the 3%NaCl solution.In contrast,the combination of CeCl3 with Ser produced a strong synergistic effect on the corrosion inhibition behavior of carbon steel,improving the inhibition efficiency significantly.The polarization curves showed that the mixture of CeCl3 and Ser acts as a cationic-type inhibitor.Scanning electron microscopy and Fourier transform infrared spectroscopy showed that the synergistic inhibition effect was due to complex formation between the cerium ions and amino acid molecules.展开更多
基金supported by the National Key Research and Development Program of China(2021YFA1500500,2019-YFA0405600)the CAS Project for Young Scientists in Basic Research(YSBR-051)+6 种基金the National Science Fund for Distinguished Young Scholars(21925204)the National Natural Science Foundation of China(22202192,U19A2015,22221003,22250007,22163002)the Collaborative Innovation Program of Hefei Science Center,CAS(2022HSCCIP004)the International Partnership,the DNL Cooperation Fund,CAS(DNL202003)the USTC Research Funds of the Double First-Class Initiative(YD9990002016,YD999000-2014)the Program of Chinese Academy of Sciences(123GJHZ2022101GC)the Fundamental Research Funds for the Central Universities(WK9990000095,WK999000-0124).
文摘Electrocatalytic water splitting provides an efficient method for the production of hydrogen.In electrocatalytic water splitting,the oxygen evolution reaction(OER)involves a kinetically sluggish four-electron transfer process,which limits the efficiency of electrocatalytic water splitting.Therefore,it is urgent to develop highly active OER catalysts to accelerate reaction kinetics.Coupling single atoms and clusters in one system is an innovative approach for developing efficient catalysts that can synergistically optimize the adsorption and configuration of intermediates and improve catalytic activity.However,research in this area is still scarce.Herein,we constructed a heterogeneous single-atom cluster system by anchoring Ir single atoms and Co clusters on the surface of Ni(OH)_(2)nanosheets.Ir single atoms and Co clusters synergistically improved the catalytic activity toward the OER.Specifically,Co_(n)Ir_(1)/Ni(OH)_(2)required an overpotential of 255 mV at a current density of 10 mA·cm^(−2),which was 60 mV and 67 mV lower than those of Co_(n)/Ni(OH)_(2)and Ir1/Ni(OH)_(2),respectively.The turnover frequency of Co_(n)Ir_(1)/Ni(OH)_(2)was 0.49 s^(−1),which was 4.9 times greater than that of Co_(n)/Ni(OH)_(2)at an overpotential of 300 mV.
文摘OBJECTIVE Hepatocel ular carcinoma(HCC)is the most common cause of cancer-related mortality,with high incidence rates,robust metastatic propensity and acquired resistance to therapy.Metformin,an extensively prescribed and well-tolerated first-linetherapeutic drug for type 2 diabetes mellitus,has recently been identified as a potential and attractive anticancer adjuvant drug combined with chemotherapeutics to improve treatment efficacy and lower doses.Curcumin,a botanical extracts,has been shown antitumorigenic properties.This study aims to investigate the combinational effect of metformin and curcumin on inbibition of tumor growth and metastasis in Hep G2 cells and the possible underlying mechanisms.METHODS The cell proliferation was determined by MTT,CCK-8 and colony formation assay.The protein expression was detected by Western blotting.Activity of MMP-2 and MMP-9 was estimated by gelatin zymography.Flow cytometry analysis was used to evaluate the influence of metformin and curcumin on cell cycle arrest and apoptosis,and morphology observation of apoptosis was detected by Hoechst33342.Scratch and transwell assay was performed to detect the cell migration and invasion.The suppression of this combination therapy oncapillary tube formation was detected by tube formation assay.RESULTS Combination of metformin and curcumin induced stronger inhibition on Hep G2 cells proliferation than monotherapywhich related to induction of cell cycle arrest in G2/M phase and apoptosis through regulation of the protein expression of cyclin B and Bcl-2/Bax.Moreover,the co-treatment of metformin with curcumin exerted an enhanced inhibitory effect on Hep G2 cell metastasis and synergistically inhibited the tube formation of HUVEC cells.The suppression of PI3K/AKT/m TOR pathway and inhibition the protein expression of STAT3,MMP9,MMP2 and VEGF might involve in this synergistic effects of combination treatment.CONCLUSION Combination of metformin and curcumin inhibited Hep G2 cells proliferationmore effectively than monotherapy and synergistically induced a greater inhibition on migration and invasion of Hep G2 cells.
基金Project(BK20140553)supported by Jiangsu Province Science Foundation for Youths,ChinaProject(51478209)supported by the National Natural Science Foundation of China
文摘In order to improve the anchoring force of anchors for carbon fiber reinforced polymer(CFRP) tendons further, a new wedge-bond-type anchor for CFRP tendons was developed. The increment in anchoring force induced by the clamping segment of anchor was studied. Taking the deformation of all parts in clamping segment in the transverse direction into consideration, the calculation formula for the increment of anchoring force was proposed based on the linear elastic hypotheses. The proposed model is verified by experiments and conclusions are drawn that the anchoring force is influenced mainly by the inclination angle of clamping pieces, the length of clamping part and the thickness of bonding medium. Especially, the thickness of bonding medium should be lowered in design to improve the synergistic effect of anchors.
基金Project(2017210101002066)supported by the Crosswise Project of Liaoning province,China
文摘The synergistic inhibition effect of CeCl3(Ce)and serine(Ser)on the corrosion of carbon steel in a 3%NaCl solution was investigated by electrochemical methods and surface analysis.The results showed that both CeCl3 and Ser,when used alone,had limited inhibition effect toward carbon steel corrosion in the 3%NaCl solution.In contrast,the combination of CeCl3 with Ser produced a strong synergistic effect on the corrosion inhibition behavior of carbon steel,improving the inhibition efficiency significantly.The polarization curves showed that the mixture of CeCl3 and Ser acts as a cationic-type inhibitor.Scanning electron microscopy and Fourier transform infrared spectroscopy showed that the synergistic inhibition effect was due to complex formation between the cerium ions and amino acid molecules.
