An analytical exploration of the effects of shear span-to-depth ratio on the shear strength of reinforced concrete beams was carried out using a meso-scale finite-element method. Prior to the numerical analysis, a method of defining concrete as meso-scale composites of multi-phases was described. The concrete was assumed to be a composite with three phases (aggregates, cement matrix and interfacial transition zone), and the material properties of each phase were applied for the numerical analysis. The shear failure behaviour of reinforced concrete beams was examined by the numerical model that was constructed, and the effect of span-to-depth ratio on shear strength was confirmed through these analyses. An investigation of cases where span-to-depth was less than 1.0 was also carried out. Moreover, the performance of the numerical model was evaluated by comparing the numerical results with the experimental results obtained from the model code and other researchers. It was confirmed that the application of a meso-scale finite-element method was appropriate for the study on the effect of span-to-depth ratio on shear strength and the occurrence and progress of bending and shear cracks.
Combination therapy employing proteins and small molecules provides access to synergistic treatment strategies. Co-delivery of these two payloads is challenging due to the divergent physicochemical properties of small molecule and protein cargos. Nanoparticle-stabilized nanocapsules (NPSCs) are promising for combination treatment strategies since they have the potential to deliver small molecule drugs and proteins simultaneously into the cytosol. In this study, we loaded paclitaxel into the hydrophobic core of the NPSC and self-assembled caspase-3 and nanoparticles on the capsule surface. The resulting combination NPSCs showed higher cytotoxicity than either of the single agent NPSCs, with synergistic action established using combination index values.
Although numerous studies on the liquefaction of lignin for the production of high-yield and high-quality bio-oil have been performed in a batch reactor, studies using a continuous flow reactor are very rare. Herein, a bench-scale continuous stirred tank reactor (CSTR) was employed for the liquefaction of lignin for the first time. Lignin obtained using a two-step concentrated acid hydrolysis process from oil palm empty fruit bunch (EFB) was used as a feedstock. The batch reactor experiment was initially conducted to select the best solvent for lignin liquefaction and investigate the effect of a formic acid (FA) additive. A bench-scale experiment then was conducted to determine how the continuous process conditions can affect the yield and composition of bio-oil. Results showed that more effective depolymerization of lignin to bio-oil is possible in the CSTR, because of the fast heating rate. The water/ethanol mixture medium at 350 °C and 28 min of space time was found to be the optimum reaction conditions to obtain a relatively high yield (51.5 wt %) and low molecular weight (597 g/mol) of bio-oil. Syringol was the most abundant monomer in bio-oils, regardless of process conditions, and higher temperature (e.g., 350 °C) was found to promote demethoxylation and alkylation reactions to produce guaiacol and alkyl guaiacol. The addition of FA to the reaction mixture not only increased the bio-oil yield from 51.5% to 60% but also reduced the O/C molar ratio of bio-oil from 0.36 to 0.30, increasing its calorific value to 27.85 MJ kg–1.
The formation and structure of tetrahydrothiophene (THT) self-assembled monolayers (SAMs) on Au(111) were examined using X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). XPS measurements revealed that THT molecules, containing endo-sulfur aliphatic rings, can form chemisorbed SAMs, in contrast with the formation of physisorbed SAMs by dialkyl monosulfide, suggesting that the adsorption ability of monosulfide compounds on gold strongly depends on the structure of tail groups, such as an aliphatic ring or two alkyl groups attached to sulfur head groups. In addition, high-resolution STM imaging revealed, for the first time, that the adsorption of THT molecules on Au(111) results in long-range, two-dimensional, ordered SAMs, having a (3 × 2√3) superlattice with many unique structural defects and a few vacancy islands. It is suggested that the unique surface structures of THT SAMs on Au(111) are mainly due to the weak van der Waals interactions between THT rings, as well as a dynamic structural variation of the THT ring in the SAMs. Our results from this study will be very useful in understanding SAM formation and the structures of organosulfur molecules containing an endo-sulfur ring.
The adoption of dynamic mechanomodulation to regulate cellular behavior is an alternative to the use of chemical drugs, allowing spatiotemporal control. However, cell-selective targeting of mechanical stimuli is challenging due to the lack of strategies with which to convert macroscopic mechanical movements to different cellular responses. Here, we designed a nanoscale vibrating surface that controls cell behavior via selective repetitive cell deformation based on a poroelastic cell model. The vibrating indentations induce repetitive water redistribution in the cells with water redistribution rates faster than the vibrating rate; however, in the opposite case, cells perceive the vibrations as a one-time stimulus. The selective regulation of cell–cell adhesion through adjusting the frequency of nanovibration was demonstrated by suppression of cadherin expression in smooth muscle cells (fast water redistribution rate) with no change in vascular endothelial cells (slow water redistribution rate). This technique may provide a new strategy for cell-type-specific mechanical stimulation.
Self-assembled monolayers (SAMs) were formed by the spontaneous adsorption of octythiocyanate (OTC) on Au(111) using both solution and ambient-pressure vapor deposition methods at room temperature and 50 °C. The surface structures and adsorption characteristics of the OTC SAMs on Au(111) were characterized by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). The STM observation showed that OTC SAMs formed in solution at room temperature have unique surface structures including the formation of ordered and disordered domains, vacancy islands, and structural defects. Moreover, we revealed for the first time that the adsorption of OTC on Au(111) in solution at 50 °C led to the formation of SAMs containing small ordered domains, whereas the SAMs formed by vapor deposition at 50 °C had long-range ordered domains, which can be described as (√3 × 2√19)R5° structures. XPS measurements of the peaks in the S 2p and N 1s regions for the OTC SAMs showed that vapor deposition is the more effective method as compared to solution deposition for obtaining high-quality SAMs by adsorption of OTC on gold. The results obtained will be very useful in understanding the SAM formation of organic thiocyanates on gold surfaces.
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