A long‐lasting particle‐based fluorescent label is designed for extended cell imaging studies. This onion‐like nanoprobe is constructed through layer‐by‐layer fabrication technology. The nanoprobes are assembled with multiple layers of optically quenched polyelectrolytes, the fluorescence signal of which can be released later by intracellular proteolysis. Upon incubation with cells, the assembled nanoprobes are taken up efficiently. The tight packing and layered assembly of the quenched polyelectrolytes slow subsequent intracellular degradation, and then result in a prolonged intracellular fluorescence signal for up to 3 weeks with no noticeable toxicity. 相似文献
Nanoparticles have great potential as nanotherapeutics, delivery vectors, and molecular imaging agents due to their flexible properties. Although intracellular and nuclear delivery of nanoparticles is desirable for therapeutic applications, it remains a challenge. Cell penetrating peptides (CPPs) are a powerful tool for the intracellular delivery of various cargoes. Here it is reported that functionalization of nanoparticles with a myristoylated oligoarginine CPP promotes cellular uptake without increased toxicity. It is evident that the myristoylated CPP is much more effective in transporting nanoparticles than the unmodified CPPs. 相似文献
A hybrid of graphene and conducting polymer holds great potential as the active materials for high performance chemical sensor application. In this work, a thin hybrid film of reduced graphene oxide (RG-O) and poly(3,4-ethylenedioxythiophene) (PEDOT) was fabricated by means of vapor phase polymerization and explored as active material for chemical sensors. The chemical sensors based on hybrid film of RG-O and PEDOT are capable of detecting electrical signals caused by the absorption of trace levels of different analyte vapors with high sensitivity, selectivity and fast response. 相似文献
Abstract Recently, Gao and Tu presented an efficient algorithm for robust low bit‐rate video transmission by using a partial backward decodable bit stream (PBDBS) approach. In this paper, we first present a multiple‐PBDBS (MPBDBS) approach to improve on the previous PBDBS approach. Next a mathematical theory is provided to minimize the error propagation length in each group of blocks (GOB). Further, a novel MPBDBS‐based algorithm is presented for robust video transmission. Experimental results demonstrate that our proposed MPBDBS‐based algorithm has better image quality when compared to the previous PBDBS‐based algorithm, but has some bit‐rate and execution‐time degradation. In our experiments, both single and two‐bit error models are investigated. 相似文献
Electrolyte additives have been widely used to address critical issues in current metal (ion) battery technologies. While their functions as solid electrolyte interface forming agents are reasonably well-understood, their interactions in the liquid electrolyte environment remain rather elusive. This lack of knowledge represents a significant bottleneck that hinders the development of improved electrolyte systems. Here, the key role of additives in promoting cation (e.g., Li+) desolvation is unraveled. In particular, nitrate anions (NO3−) are found to incorporate into the solvation shells, change the local environment of cations (e.g., Li+) as well as their coordination in the electrolytes. The combination of these effects leads to effective Li+ desolvation and enhanced battery performance. Remarkably, the inexpensive NaNO3 can successfully substitute the widely used LiNO3 offering superior long-term stability of Li+ (de-)intercalation at the graphite anode and suppressed polysulfide shuttle effect at the sulfur cathode, while enhancing the performance of lithium–sulfur full batteries (initial capacity of 1153 mAh g−1 at 0.25C) with Coulombic efficiency of ≈100% over 300 cycles. This work provides important new insights into the unexplored effects of additives and paves the way to developing improved electrolytes for electrochemical energy storage applications. 相似文献
We report a procedure to prepare a conducting nano-composites composed of multi-walled carbon nanotubes (MWNTs) and PEDOT by using a poly(sodium 4-styrenesulfonate) (PSSNa) as a inter-linking molecule between MWNT and PEDOT. When PSSNa chains are introduced on the MWNTs via physicochemical interaction, the surface of MWNT becomes negatively charged, and PSS-modified MWNTs promote the effective association of the positively charged PEDOT chains. The resulting MWNT-PSS/PEDOT composites are characterized by a better interconnection between MWNT and PEDOT components. 相似文献
The selective wetting behavior of silica in emulsion styrene butadiene rubber (ESBR)/solution styrene butadiene rubber (SSBR) blends is characterized by the wetting concept, which is further developed for filled blends based on miscible rubbers. It is found that not only the chemical rubber–filler affinity but also the topology of the filler surface significantly influences the selective filler wetting in rubber blends. The nanopore structure of the silica surface has been recognized as the main reason for the difference in the wetting behavior of the branched ESBR molecules and linear SSBR molecules. However, the effect of nanopore structure becomes more significant in the presence of silane. It is discussed that the adsorption of silane on silica surface constricts the nanopore to some extent that hinders effectively the space filling of the nanopores by the branched ESBR molecules but not by the linear SSBR molecules. As a result, in silanized ESBR/SSBR blends the dominant wetting of silica surface by the tightly bonded layer of SSBR molecules causes a low‐energy dissipation in the rubber–filler interphase. That imparts the low rolling resistance to the blends similar to that of a silica‐filled SSBR compound, while the ESBR‐rich matrix warrants the good tensile behavior, i.e., good abrasion and wear resistance of the blends.