AFM （atomic force microscopy） technology was applied on C-S-H （calcium silicate hydrate phase） microstructure investigation. The topographies of hydrated C3S （Tricalcium silicate） samples were firstly acquired w...AFM （atomic force microscopy） technology was applied on C-S-H （calcium silicate hydrate phase） microstructure investigation. The topographies of hydrated C3S （Tricalcium silicate） samples were firstly acquired with AFM. Accordingly, C-S-H can be identified according its pattern. Then the hydrated pssortland cement samples at different curing time were scanned with AFM. The topographies and force displacement curve were acquired and its characters at different days were summarized and analyzed. These results are very meaningful for C-S-H microstructure further investigation and cement-base material macro scale properties improvement.展开更多
All living cells in a human body are made of the same DNA molecule but cells in different tissues express different genes and proteins.How the transcription process is controlled and regulated is largely unknown.Speci...All living cells in a human body are made of the same DNA molecule but cells in different tissues express different genes and proteins.How the transcription process is controlled and regulated is largely unknown.Specifically,mechanical forces are increasingly recognized to play critical roles in cell and tissue functions.However,what controls force-induced gene transcription is elusive.Recently we have reported that a local surface force transfers from integrins to the cytoskeleton and the link of nucleoskeleton and the cytoskeleton(LINC)into the nucleus and deforms chromatin directly to induce rapid activation of transgene DHFR.Here we show that endogenous mechanoresponsive genes egr-1 and Cav1 are rapidly upregulated and their upregulation depends on stress angles relative to the cell long axis,suggesting direct impact of these genes by force.Demethylation of histone 3 at lysine 9(H3K9)trimethylation(H3K9me3)at nuclear interiors(euchromatin)is necessary for force-induced transcription upregulation.Our findings suggest that force-rapid upregulation of mechanoresponsive genes by force depends on H3K9me3 demethylation.展开更多
A numerical investigation is carried out to study the effect of splitter＇s inclination angle behind an inclined square cylinder on the forced convection heat transfer in a plan channel using the lattice Boltzmann met...A numerical investigation is carried out to study the effect of splitter＇s inclination angle behind an inclined square cylinder on the forced convection heat transfer in a plan channel using the lattice Boltzmann method （LBM）. The simulations are conducted for the pertinent parameters in the following ranges： the Reynolds number Re=50-300, the gap ratio G/d = 2, and the splitter＇s inclination angle 8 = 0°-90°. The results show that with the increase in the angle of the splitter, the drag coefficient initially decreases and then increases. Moreover, the time-averaged Nusselt number at a certain angle increases noticeably.展开更多
基金Funded by the "973" Project (No. 2009CB623200)the National Natural Science Foundation of China (50972109)
文摘AFM （atomic force microscopy） technology was applied on C-S-H （calcium silicate hydrate phase） microstructure investigation. The topographies of hydrated C3S （Tricalcium silicate） samples were firstly acquired with AFM. Accordingly, C-S-H can be identified according its pattern. Then the hydrated pssortland cement samples at different curing time were scanned with AFM. The topographies and force displacement curve were acquired and its characters at different days were summarized and analyzed. These results are very meaningful for C-S-H microstructure further investigation and cement-base material macro scale properties improvement.
基金supported by the funds from Huazhong University of Science and Technology and US NIH grant GM 072744
文摘All living cells in a human body are made of the same DNA molecule but cells in different tissues express different genes and proteins.How the transcription process is controlled and regulated is largely unknown.Specifically,mechanical forces are increasingly recognized to play critical roles in cell and tissue functions.However,what controls force-induced gene transcription is elusive.Recently we have reported that a local surface force transfers from integrins to the cytoskeleton and the link of nucleoskeleton and the cytoskeleton(LINC)into the nucleus and deforms chromatin directly to induce rapid activation of transgene DHFR.Here we show that endogenous mechanoresponsive genes egr-1 and Cav1 are rapidly upregulated and their upregulation depends on stress angles relative to the cell long axis,suggesting direct impact of these genes by force.Demethylation of histone 3 at lysine 9(H3K9)trimethylation(H3K9me3)at nuclear interiors(euchromatin)is necessary for force-induced transcription upregulation.Our findings suggest that force-rapid upregulation of mechanoresponsive genes by force depends on H3K9me3 demethylation.
文摘A numerical investigation is carried out to study the effect of splitter＇s inclination angle behind an inclined square cylinder on the forced convection heat transfer in a plan channel using the lattice Boltzmann method （LBM）. The simulations are conducted for the pertinent parameters in the following ranges： the Reynolds number Re=50-300, the gap ratio G/d = 2, and the splitter＇s inclination angle 8 = 0°-90°. The results show that with the increase in the angle of the splitter, the drag coefficient initially decreases and then increases. Moreover, the time-averaged Nusselt number at a certain angle increases noticeably.
