In the present study, cellulose whiskers were incorporated into nanofibers of polyethylene oxide (PEO) by the electrospinning process to enhance the mechanical properties of the electrospun PEO fibers. Cellulose whiskers consisting of highly crystalline rod-like particles with a high aspect ratio and specific area were obtained by the acid hydrolysis of bacterial cellulose microfibrils. From the transmission electron microscopy (TEM) images of the bacterial cellulose whiskers, their length was measured to be 420 AE 190 nm and their width 11 AE 4 nm. The height of the whiskers was measured to be 10 AE 2 nm by atomic force microscopy. The successful formation of electrospun fibers with a diameter of less than 1 mm and well-embedded microfibrils was confirmed by scanning electron microscopy and TEM.
Bound-state (BS) formation in quantum point contacts (QPCs) may offer a convenient way to localize and probe single spins. In this letter, we investigate how such BSs are affected by monitoring them with a second QPC, which is coupled to the BS via wavefunction overlap. We show that this coupling leads to a unique detector backaction, in which the BS is weakened by increasing its proximity to the detector. We also show, however, that this interaction between the QPCs can be regulated at will, by using an additional gate to control their wavefunction overlap.
Large amounts of nanomaterials may reach both the natural and occupational environments. This represents a potential health hazard. People have forecasted that CNTs may lead to the toxicity such as mesothelioma and fibrosis like asbestos. To identify dominant immune responses induced by SWCNTs, we investigated the composition of bronchioalveolar lavage (BAL) cells, the secretion of cytokine and collagen, histopathology, protein expression, and cell phenotypes over time after a single administration of single-walled carbon nanotubes (SWCNT). In our results, the number of total cells and macrophages remained at the up-regulated level until Day 28, neutrophils rapidly increased at Day 1, and lymphocytes increased from Day 7. In the BAL fluid, pro-inflammatory cytokines rapidly increased at Day 1 and remained at an up-regulated level throughout the experimental period. IL-12 and IL-10 rapidly increased at Day 1 after administration and remained at a similar level until Day 28. IFN-γ and IL-4 reached the maximum at Day 1, and IL-5, TGF-β, and collagen reached the maximum at Day 7. IL-13 and IL-17 increased in a time-dependent manner. The distribution of B cells and cytotoxic T cells markedly increased at Days 7 and 14, and fibrotic lesions were histopathologically observed at Days 7 and 14. The expressions of caspase-3, p53, COL1A1, COX-2, iNOS, MMP-9, and MMP-2 were also markedly increased at Days 7 and 14. In addition, the expression of mesothelin, iNOS, MMP-9, and p53 was up-regulated until Day 28. Based on these findings, we suggest that a single intratracheal instillation of SWCNTs may induce early lung fibrosis and subchronic tissue damage.
Summary: A simple and mass‐producible method was developed to densely assemble multiwalled carbon nanotubes (MWNTs) onto electrospun nylon 6 nanofibrous membranes. The process consists of dispersing the acid‐treated MWNTs in surfactant solutions or organic solvents, and dipping the nanofibrous membranes in the resulting dispersion for only 60 seconds, followed by the extraction of the surfactants in pure water and drying. The conductivity of the MWNT‐adsorbed nanofibrous membranes ranges from 2.2 × 10−2 to 1.5 × 10−1 S · cm−1, as determined by the four probe method, which implies that the MWNTs are adsorbed uniformly and densely along the nanofibrous membranes. Furthermore, the results suggest that there is a strong interaction between the acid‐treated MWNTs and nylon 6. We also investigate the amount of MWNTs present in the membranes using thermogravimetric analysis.SEM images of the non‐woven fibrous nylon 6 membranes after dip‐coating in a dispersion of the MWNTs in surfactant‐containing water.imageSEM images of the non‐woven fibrous nylon 6 membranes after dip‐coating in a dispersion of the MWNTs in surfactant‐containing water.
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