In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-...In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-TPR that plasma treatment can enhance the interaction between Ni O/Ni particles and the YZrOpyrochlore support. Therefore, catalysts with smaller Ni O and Ni grains sizes, higher metallic Ni active surface areas can be achieved, as evidenced by XRD, TEM and Hadsorption-desorption measurements. As a consequence, the plasma-treated catalysts show significantly improved activity, stability and coke resistance, as testified by the TEM and TGA-DSC results. Plasma treatment in H/Ar gas mixture is found to be the best condition to prepare Ni/YZrO, which can be used to obtain a catalyst with the highest activity, stability and most potent coke resistance. It is believed that the smaller Ni grain size and higher metallic Ni active surface area induced by plasma treatment are the inherent reasons accounting for the promoted reaction performance of the Ni/YZrOpyrochlore catalysts.展开更多
Dear Editor Despite remarkable advances in our understanding of brain functions,the neural substrates and correlates of consciousness remain unclear[1].It has been argued that classical physics is intrinsically incapa...Dear Editor Despite remarkable advances in our understanding of brain functions,the neural substrates and correlates of consciousness remain unclear[1].It has been argued that classical physics is intrinsically incapable of explaining the holistic aspects of consciousness.展开更多
[Object]This study aimed to examine the effects of 3,7-dimethyl-1-（5-oxo-hexyl）-xanthine（pentoxifylline,PF）on the motility,mitochondrial activity,acrosome integrity and fertilization rate of spermatozoa in both fr...[Object]This study aimed to examine the effects of 3,7-dimethyl-1-（5-oxo-hexyl）-xanthine（pentoxifylline,PF）on the motility,mitochondrial activity,acrosome integrity and fertilization rate of spermatozoa in both fresh and frozen-thawed bull semen.[Method]Fresh and frozen-thawed bull spermatozoa were exposed to 5 mmol/L PF with untreated samples as controls.[Result]Fresh spermatozoa showed reduced（P〈0.05）motility after 2 h incubation with PF whereas,surprisingly,frozen-thawed samples exhibited increased sperm motility（P〈0.05）after 2 h incubation with PF and they also showed enhanced longevity compared to controls.Mitochondrial activity in both fresh and frozen-thawed bull spermatozoa increased（P〈0.05）during 4 h incubation with PF whereas acrosome integrity remained unchanged in both types of semen.However,treatment with 5 mmol/L PF did not influence the in vitro fertilization efficiency of fresh spermatozoa but improved significantly（P〈0.05）that of frozen-thawed spermatozoa.[Conclusion]These results indicate that PF can improve sperm quality of frozenthawed bull semen,and may improve pregnancy rates in bovine artificial insemination programmes employing frozen semen.展开更多
We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe(EP)and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength telescopes.The new transient was fi...We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe(EP)and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength telescopes.The new transient was first detected with Wide-field X-ray Telescope(WXT)on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for 12 s.The flare reached a peak flux of 3:9×10^(−9) erg cm^(−2) s^(−1) in 0.5-4 keV,∼300 times brighter than the underlying X-ray emission detected throughout the observation.Rapid and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new transient.Its X-ray spectrum is non-thermal in 0.5-10 keV,with a power-law photon index varying within 1.8-2.5.The X-ray light curve shows a plateau lasting for∼4 d,followed by a steep decay till becoming undetectable∼10 d after the initial detection.Based on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term transients.No counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these bands.We demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical transients.The nature of EP240408a thus remains an enigma.We suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of∼10 d.The detection and follow-ups of more of such objects are essential for revealing their origin.展开更多
Detection of sentinel lymph nodes(SLNs)is critical to guide the treatment of breast cancer.However,distinguishing metastatic SLNs from normal and inflamed lymph nodes(LNs)during surgical resection remains a challenge....Detection of sentinel lymph nodes(SLNs)is critical to guide the treatment of breast cancer.However,distinguishing metastatic SLNs from normal and inflamed lymph nodes(LNs)during surgical resection remains a challenge.Here,we report a CD44 and scavenger receptor class B1 dual-targeting hyaluronic acid nanoparticle(5K-HA-HPPS)loaded with the near-infra-red fluorescent dye DiR-BOA for SLN imaging in breast cancer.The small sized(~40 nm)self-assembled 5K-HA-HPPSs accumulated rapidly in the SLNs after intradermal injection.Compared with normal popliteal LNs(N-LN),there were ~3.2-fold and ~2.4-fold increases in fluorescence intensity in tumour metastatic SLNs(T-MLN)and inflamed LNs(Inf-LN),respectively,6 h after nanoparticle inoculation.More importantly,photoacoustic microscopy(PAM)of 5KHA-HPPS showed a significantly distinct distribution in T-MLN compared with N-LN and Inf-LN.Signals were mainly distributed at the centre of T-MLN but at the periphery of N-LN and Inf-LN.The ratio of PA intensity(R)at the centre of the LNs compared with that at the periphery was 5.93±0.75 for T-MLNs of the 5K-HA-HPPS group,which was much higher than that for the Inf-LNs(R=0.2±0.07)and N-LNs(R=0.45±0.09).These results suggest that 5K-HA-HPPS injection combined with PAM provides a powerful tool for distinguishing metastatic SLNs from pLNs and inflamed LNs,thus guiding the removal of SLNs during breast cancer surgery.展开更多
基金supported by the National Natural Science Foundation of China (21567016, 21566022, 21263015)the Natural Science Foundation of Jiangxi Province (20151BBE50006, 20151BAB203024)the Education Department of Jiangxi Province (KJLD14005, GJJ150016)
文摘In this study, Ni/YZrOcatalysts prepared with impregnation method and treated by dielectric barrier discharge plasma(DBD) in different atmospheres have been investigated for methane dry reforming. It is revealed by H-TPR that plasma treatment can enhance the interaction between Ni O/Ni particles and the YZrOpyrochlore support. Therefore, catalysts with smaller Ni O and Ni grains sizes, higher metallic Ni active surface areas can be achieved, as evidenced by XRD, TEM and Hadsorption-desorption measurements. As a consequence, the plasma-treated catalysts show significantly improved activity, stability and coke resistance, as testified by the TEM and TGA-DSC results. Plasma treatment in H/Ar gas mixture is found to be the best condition to prepare Ni/YZrO, which can be used to obtain a catalyst with the highest activity, stability and most potent coke resistance. It is believed that the smaller Ni grain size and higher metallic Ni active surface area induced by plasma treatment are the inherent reasons accounting for the promoted reaction performance of the Ni/YZrOpyrochlore catalysts.
基金supported by the National Natural Science Foundation of China (31640034)the Sci-Tech Support Plan of Hubei Province, China (2014BEC086)the Research Team Fund of the South-Central University for Nationalities, China (XTZ15014)
文摘Dear Editor Despite remarkable advances in our understanding of brain functions,the neural substrates and correlates of consciousness remain unclear[1].It has been argued that classical physics is intrinsically incapable of explaining the holistic aspects of consciousness.
基金Supported by NMKJ Project of Production and Industrial Application of Sexed Semen in Domestic Animals(No.20111701)
文摘[Object]This study aimed to examine the effects of 3,7-dimethyl-1-（5-oxo-hexyl）-xanthine（pentoxifylline,PF）on the motility,mitochondrial activity,acrosome integrity and fertilization rate of spermatozoa in both fresh and frozen-thawed bull semen.[Method]Fresh and frozen-thawed bull spermatozoa were exposed to 5 mmol/L PF with untreated samples as controls.[Result]Fresh spermatozoa showed reduced（P〈0.05）motility after 2 h incubation with PF whereas,surprisingly,frozen-thawed samples exhibited increased sperm motility（P〈0.05）after 2 h incubation with PF and they also showed enhanced longevity compared to controls.Mitochondrial activity in both fresh and frozen-thawed bull spermatozoa increased（P〈0.05）during 4 h incubation with PF whereas acrosome integrity remained unchanged in both types of semen.However,treatment with 5 mmol/L PF did not influence the in vitro fertilization efficiency of fresh spermatozoa but improved significantly（P〈0.05）that of frozen-thawed spermatozoa.[Conclusion]These results indicate that PF can improve sperm quality of frozenthawed bull semen,and may improve pregnancy rates in bovine artificial insemination programmes employing frozen semen.
基金based on data obtained with Einstein Probe,a space mission supported by Strategic Priority Program on Space Science of Chinese Academy of Sciences,in collaboration with ESA,MPE and CNES(Grant No.XDA15310000)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0550200)+5 种基金the National Key R&D Program of China(Grant No.2022YFF0711500)the support by the National Natural Science Foundation of China(Grant Nos.12333004,12321003,12103065,12373040,12021003,12025303,12393814,and 12203071)the China Manned Space Project(Grant Nos.CMS-CSST-2021-A13,and CMS-CSST-2021-B11)the Youth Innovation Promotion Association of the Chinese Academy of Sciencessupported by a Ramón y Cajal fellowship(Grant No.RYC2021-030888-I)financial support from AGAUR,CSIC,MCIN and AEI 10.13039/501100011033(Grant Nos.PID2023-151307NB-I00,PIE 20215AT016,CEX2020-001058-M,and 2021-SGR-01270)。
文摘We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe(EP)and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength telescopes.The new transient was first detected with Wide-field X-ray Telescope(WXT)on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for 12 s.The flare reached a peak flux of 3:9×10^(−9) erg cm^(−2) s^(−1) in 0.5-4 keV,∼300 times brighter than the underlying X-ray emission detected throughout the observation.Rapid and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new transient.Its X-ray spectrum is non-thermal in 0.5-10 keV,with a power-law photon index varying within 1.8-2.5.The X-ray light curve shows a plateau lasting for∼4 d,followed by a steep decay till becoming undetectable∼10 d after the initial detection.Based on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term transients.No counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these bands.We demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical transients.The nature of EP240408a thus remains an enigma.We suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of∼10 d.The detection and follow-ups of more of such objects are essential for revealing their origin.
基金supported by the National Science Fund for Distinguished Young Scholars(81625012)the National Natural Science Foundation of China(61721092)+2 种基金the Fundamental Research Funds for the Central Universities(2019kfyXMBZ022)Programme for HUST Academic Frontier Youth Team(Zhang,Z.H.)the Innovation Fund of WNLO.
文摘Detection of sentinel lymph nodes(SLNs)is critical to guide the treatment of breast cancer.However,distinguishing metastatic SLNs from normal and inflamed lymph nodes(LNs)during surgical resection remains a challenge.Here,we report a CD44 and scavenger receptor class B1 dual-targeting hyaluronic acid nanoparticle(5K-HA-HPPS)loaded with the near-infra-red fluorescent dye DiR-BOA for SLN imaging in breast cancer.The small sized(~40 nm)self-assembled 5K-HA-HPPSs accumulated rapidly in the SLNs after intradermal injection.Compared with normal popliteal LNs(N-LN),there were ~3.2-fold and ~2.4-fold increases in fluorescence intensity in tumour metastatic SLNs(T-MLN)and inflamed LNs(Inf-LN),respectively,6 h after nanoparticle inoculation.More importantly,photoacoustic microscopy(PAM)of 5KHA-HPPS showed a significantly distinct distribution in T-MLN compared with N-LN and Inf-LN.Signals were mainly distributed at the centre of T-MLN but at the periphery of N-LN and Inf-LN.The ratio of PA intensity(R)at the centre of the LNs compared with that at the periphery was 5.93±0.75 for T-MLNs of the 5K-HA-HPPS group,which was much higher than that for the Inf-LNs(R=0.2±0.07)and N-LNs(R=0.45±0.09).These results suggest that 5K-HA-HPPS injection combined with PAM provides a powerful tool for distinguishing metastatic SLNs from pLNs and inflamed LNs,thus guiding the removal of SLNs during breast cancer surgery.
