Cell morphology and nucleus deformation are important when circulating tumor cells break away from the primary tumor and migrate to a distant organ. Cells are sensitive to the microenvironment and respond to the cell-material interfaces. We fabricated TiO nanorod arrays with mesoscopic micro-nano interfaces through a two-step hydrothermal reaction method to induce severe changes in cell morphology and nucleus deformation. The average size of the microscale voids was increased from 5.1 to 10.5 μm when the hydrothermal etching time was increased from 3 to 10 h, whereas the average distances between voids were decreased from 0.88 to 0.40 μm. The nucleus of the MCF-7 cells on the TiO nanorod substrate that was etched for 10 h exhibited a significant deformation, because of the large size of the voids and the small distance between voids. Nucleus defromation was reversible during the cells proliferate process when the cells were cultured on the mesoscopic micro-nano interface.This reversible process was regulated by combining of the uniform pressure applied by the actin cap and the localized pressure applied by the actin underneath the nucleus. Cell morphology and nucleus shape interacted with each other to adapt to the microenvironment. This mesoscopic micro-nano interface provided a new insight into the cell-biomaterial interface to investigate cell behaviors.
Mortar has an important influence on the viscosity and durability of a mixture. The effects of the amount of mineral powder in asphalt mortar on the ultraviolet (UV) aging properties of asphalt were investigated by a Fourier transform infrared spectrum (FTIR), gel permeation chromatography (GPC), and dynamic shear rheometer (DSR). The FTIR results show that the UV-resistant aging ability of asphalt mortar was superior to asphalt and that the carbonyl indices of the SBS- (styrene-butadiene-styrene-) asphalt mortar and matrix asphalt mortar were more significant. The GPC results show that the molecular weight distribution coefficient (Mw/Mn) of the SBS-asphalt-filler mastic is 1.0 and that of the matrix asphalt-filler mastic is 1.2, which is the largest. The macro-property is the most stable. The DSR results show that the matrix asphalt-filler mastic ranging from 1.0 to 1.2 and the SBS-modified asphalt-filler mastic ranging from 0.8 to 1.0 show the best UV aging resistance. Therefore, the effects of the amount of mineral powder cannot be ignored, suggesting that the best mass ratio of the matrix asphalt mortar is 1.2 and that of the SBS-modified asphalt mortar is 1.0 during the UV aging process.
A soft metal salt assisted electrospray ionization mass spectrometry has been developed to characterize directly GAP polymers through the complexing effect of anions from metal salts with glycidyl azide polymers (GAP) in a negative ion mode.
Droplet‐based technologies, which utilize the surface charge characterization of droplets, are used in fluorescence‐activated cell sorting and energy harvesting. Herein, the influence of droplet charges on microchips is investigated via surface engineering. An electrical field is applied to deflect the droplets in a microchannel, thereby enabling a qualitative analysis of the droplet charge. In a glass polydimethylsiloxane (PDMS)‐boned microchip, the droplet charge decreases when the microchannel is changed from a single‐sided to a three‐sided rectangular microstructure. When the ionic concentration of the droplet increases from 1 μm to 10 mm, droplet charges decrease by ≈78%. Meanwhile, a Au film is patterned in the microchannel, and 11‐aminoundecanethiol hydrochloride (AUT) and 12‐mercaptododecanoic acid (MDA) are modified to modulate the Au surface characterization. Compared with the glass–PDMS‐bonded microchannel, the Au film can suppress the streaming potential to decrease the droplet charges. After modification with MDA and AUT, the droplet charges increase. Therefore, the microchannel structures, ionic concentration, and substrate surface properties can be utilized to modulate the droplet charges, which can be widely used in droplet‐based energy harvesting and biological and chemical sample sorting.
The effect of acid concentration in nitrocellulose (NC) on thermal stability of NC for civil use was studied using differential scanning calorimeter (DSC). The thermal explosion temperature (Tb) and kinetic parameters of NC thermal decomposition were calculated using different methods based on the thermal decomposition behaviors of NC in high pressure-gold plated stainless steel crucible at different heating rates. The results show that acid content in NC reduces the stability of NC remarkably, including reducing the characteristic decomposition temperature such as peak temperature (Tp), onset temperature (Tonset), initial temperature (T0) and critical temperature of thermal explosion (Tb). The big difference between NC with different acid content is that the relative quantity of activation energy and the change trend of activation energy. The most interesting thing is that NC with more acid content has the lower characteristic temperature but higher calculated activation energy.
Correction for ‘Metal salt assisted electrospray ionization mass spectrometry for the soft ionization of GAP polymers in negative ion mode’ by Theoneste Muyizere et al., Analyst, 2020, 145, 34–45.
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