[Objective] The study aims to determine the optimal concentration of trypsin for the proliferation of avian influenza virus （AIV） H9N2 subtype in Madin- Darby canine kidney （MDCK） cells. [Method] Three AIV H9 subt...[Objective] The study aims to determine the optimal concentration of trypsin for the proliferation of avian influenza virus （AIV） H9N2 subtype in Madin- Darby canine kidney （MDCK） cells. [Method] Three AIV H9 subtype isolates were inoculated on MDCK cells respectively. Then, DMEM containing different concentrations of trypsin as maintenance media were added to MDCK monolayer cells. The cytopathic effect （CPE） was observed once every 24 h, and the HA titer of the supematant was measured by HA assay. [Result] When the trypsin concentration was 10 -20 μg/ml in DMEM, the HA titer of virus culture reached 7 log2 （1：128）. Almost all cells were cytopathic after 96 h post inoculation with 1：1 000 or 1：10 000 dilution of AIV culture, and the virus titer reached a peak after 72 -96 h. [ Conclusion] The optimal concentration of trypsin is 10 -20 pg/ml for proliferation of AIV H9N2 subtype in MDCK cells.展开更多
Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness,high element abundance,and low cost.Here,we developed a strategy of one-step ga...Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness,high element abundance,and low cost.Here,we developed a strategy of one-step gas-solid-phase diffusioninduced reaction to fabricate a series of bandgap-tunable Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI bilayer films due to the atomic diffusion effect for the first time.By designing and regulating the sputtered Cu/Ag/Bi metal film thickness,the bandgap of Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI could be reduced from 2.06 to 1.78 eV.Solar cells with the structure of FTO/TiO_(2)/Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI/carbon were constructed,yielding a champion power conversion efficiency of 2.76%,which is the highest reported for this class of materials owing to the bandgap reduction and the peculiar bilayer structure.The current work provides a practical path for developing the next generation of efficient,stable,and environmentally friendly photovoltaic materials.展开更多
Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce th...Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce the 2n pollen formation by high temperature treatment.This study focused on the optimization of the 2n pollen induction technique and the mechanisms of high temperature-induced2n pollen formation in C.oleifera.We found that the optimal protocol for inducing 2n pollen via high temperature was to perform 45℃with4 h at the prophaseⅠstage of the pollen mother cells(PMCs).Meanwhile,high temperature significantly decreased the yield and fertility of2n pollen.Through the observation of meiosis,abnormal chromosome and cytological behaviour was discovered under high-temperature treatment,and we confirmed that the formation of 2n pollen is caused by abnormal cell plate.Based on weighted gene co-expression network analysis,fifteen hub genes related to cell cycle control were identified.After male flower buds were exposed to heat shock,polygalacturonase gene(CoPGX3)was significantly upregulated.We inferred that high temperature causes the CoPGX3 gene to be overexpressed and that CoPGX3 is redistributed into the cytosol where it degrades cytoplasmic pectin,which leads to an abnormal cell plate.Furthermore,abnormal cytokinesis resulted in the formation of dyads and triads,and PMCs divided to produce 2n pollen.Our findings provide new insights into the mechanism of 2n pollen induced by high temperature in a woody plant and lay a foundation for further ploidy breeding of C.oleifera.展开更多
基金funded by the Beijing Academy of Agriculture and Forestry Sciences (2010A007)
文摘[Objective] The study aims to determine the optimal concentration of trypsin for the proliferation of avian influenza virus （AIV） H9N2 subtype in Madin- Darby canine kidney （MDCK） cells. [Method] Three AIV H9 subtype isolates were inoculated on MDCK cells respectively. Then, DMEM containing different concentrations of trypsin as maintenance media were added to MDCK monolayer cells. The cytopathic effect （CPE） was observed once every 24 h, and the HA titer of the supematant was measured by HA assay. [Result] When the trypsin concentration was 10 -20 μg/ml in DMEM, the HA titer of virus culture reached 7 log2 （1：128）. Almost all cells were cytopathic after 96 h post inoculation with 1：1 000 or 1：10 000 dilution of AIV culture, and the virus titer reached a peak after 72 -96 h. [ Conclusion] The optimal concentration of trypsin is 10 -20 pg/ml for proliferation of AIV H9N2 subtype in MDCK cells.
基金supported by National Natural Science Foundation of China(Grant No.52072327,62074052,61874159)Zhongyuan Thousand Talents(Zhongyuan Scholars)Program of Henan Province(202101510004)+6 种基金Higher Education and Teaching Reformation Project(2014SJGLX064)Academic Degrees&Graduate Education Reform Project of Henan Province(2021SJGLX060Y)Key research and development projects of Universities in Henan Province(20A140026)the Scientific Research Innovation Team of Xuchang University(2022CXTD008)Science and Technology Project of Henan Province(222102230009).L.Ding thanks the National Key Research and Development Program of China(2022YFB3803300)the open research fund of Songshan Lake Materials Laboratory(2021SLABFK02)the National Natural Science Foundation of China(21961160720).
文摘Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness,high element abundance,and low cost.Here,we developed a strategy of one-step gas-solid-phase diffusioninduced reaction to fabricate a series of bandgap-tunable Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI bilayer films due to the atomic diffusion effect for the first time.By designing and regulating the sputtered Cu/Ag/Bi metal film thickness,the bandgap of Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI could be reduced from 2.06 to 1.78 eV.Solar cells with the structure of FTO/TiO_(2)/Cu_(a)Agm_(1)Bim_(2)I_(n)/CuI/carbon were constructed,yielding a champion power conversion efficiency of 2.76%,which is the highest reported for this class of materials owing to the bandgap reduction and the peculiar bilayer structure.The current work provides a practical path for developing the next generation of efficient,stable,and environmentally friendly photovoltaic materials.
基金supported by the National Natural Science Foundation of China(Grant No.32101489)Forestry Science and Technology Innovation Program of Hunan Province(Grant No.XLK202101-2)Science and Technology Innovation Platform and Talent Program of Hunan Province(Grant Nos.2023RC3164,2021NK1007)。
文摘Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce the 2n pollen formation by high temperature treatment.This study focused on the optimization of the 2n pollen induction technique and the mechanisms of high temperature-induced2n pollen formation in C.oleifera.We found that the optimal protocol for inducing 2n pollen via high temperature was to perform 45℃with4 h at the prophaseⅠstage of the pollen mother cells(PMCs).Meanwhile,high temperature significantly decreased the yield and fertility of2n pollen.Through the observation of meiosis,abnormal chromosome and cytological behaviour was discovered under high-temperature treatment,and we confirmed that the formation of 2n pollen is caused by abnormal cell plate.Based on weighted gene co-expression network analysis,fifteen hub genes related to cell cycle control were identified.After male flower buds were exposed to heat shock,polygalacturonase gene(CoPGX3)was significantly upregulated.We inferred that high temperature causes the CoPGX3 gene to be overexpressed and that CoPGX3 is redistributed into the cytosol where it degrades cytoplasmic pectin,which leads to an abnormal cell plate.Furthermore,abnormal cytokinesis resulted in the formation of dyads and triads,and PMCs divided to produce 2n pollen.Our findings provide new insights into the mechanism of 2n pollen induced by high temperature in a woody plant and lay a foundation for further ploidy breeding of C.oleifera.
