Carbon nanotubes (CNTs) show extraordinary multifunctionality, including excellent mechanical, electrical and thermal properties. To be used in practical applications, the CNTs need to be assembled into macroscale structures such as films, fibers and composites. Unfortunately, so far the properties of these macro-structures have been very poor, usually one to three orders of magnitude lower than that of individual CNTs. Low CNT structural perfection, alignment and intertube interaction are key issues that are responsible for such disappointing properties. Researchers have now demonstrated a simple, efficient and scalable strategy to make CNT films ultra-strong and conductive, in which the CNTs are well aligned and densely packed by exploiting drawable CNT arrays as precursors.
One type of biomolecules, enzymes, regulate almost all chemical reactions involved in numerous biological processes in living organisms and are also widely used in research and industry. Regulation of enzyme activity and stability is very important and has always attracted great attention. Various enzyme regulators, ranging from proteins, peptides, and synthetic organic molecules, have been discovered. Recently, nanomaterials evolve as promising alternatives for enzyme modulation. Nanomaterials provide large surface areas for biomolecule adsorption and can be engineered to present multiple surface functional groups for interacting with biomolecules, such as enzymes and/or their substrates. In a recent study, scientists started to explore the interactions between functionalized graphene oxide and serine proteases, a large family of enzymes with important biomedical and industrial applications.
An international group of researchers reported a new record long distance for quantum teleportation. The authors claim a free-space distance of 143 kilometers. Quantum teleportation communicates physical information soundly without traveling directly through the space connecting the communicating parties. The reporting team includes quantum teleportation pioneer Anton Zeilinger of the Quantum Optics, Quantum Nanophysics, Quantum Information at the University of Vienna. Quantum teleportation combines classical and quantum information channels to transmit the complex state of quantum particles. The communication method conveys complete quantum information without the need to pass directly through the space between communicating parties.
New research explores the uses of time reversal symmetry in optics, with a focus on quantum optics. The article compares time reversal with optical phase conjugation, and illustrates the concept of time reversal symmetry with several examples in classical and quantum optics. Time reversal symmetry is the physical property that events can occur in a forward or backward direction through time, with no fundamental distinction due to the direction. Time reversal symmetry applies to both classical and quantum optics, as well as areas of physics outside of optics. The property holds true in all areas of physics, with possible exceptions only under rare conditions in particle physics.
Modifying living cell by coating them with a nanolayer of functional materials in order to provide them with new structural and functional features has developed into a popular research area for bionanotechnology researchers. In contrast to genetic manipulation techniques, here the functionality of a cell is modified simply by attaching polymers or nanoparticles to the cell's surface. A recent Perspective paper covers the most interesting and promising work in this area and presents an outlook the major potential future directions. The article focuses on on cell encapsulation with Layer-by-Layer (LbL) self-assembly via sequential adsorption of oppositely charged components: polyelectrolytes, nanoparticles, and proteins.
Researchers in China showed that nanoparticles smaller than 10 nm in diameter accumulate more efficiently and penetrate more deeply in tumors relative to their larger counterparts. Their findings have significant implications for the development of nanomaterials to diagnose and treat cancer. The enhanced tumor accumulation of the ultrasmall nanoparticles may be due, at least in part, to their prolonged blood circulation time. In contrast, most nanomaterials that enter the blood are rapidly cleared by tissue-resident macrophages in the liver and spleen. Ultimately, the ability of ultrasmall nanoparticles to diffuse deep within the tumor bulk may enable the design of nanoparticles that can carry therapeutic and diagnostic agents more efficiently into tumors.
A substance might potentially be harmful or even toxic for a biological system, provided that the quantity or the concentration (the "dose") is high enough. This principle forms the basis for health standards which determine the maximum permissible concentration of contaminations, for example in food, water or in the environment. Dose calculation is of high relevance for risk assessment as well as for regulations, for instance to determine the maximum allowable concentration of chemicals and particles or to determine other limits which do not cause health problems. In the case of nanomaterials, especially for nanoparticles there is to date, no limit regulation or any other regulation referring to dose, because the definition of dose for nanoparticles does not exist. The wherefores will be explained in this dossier.
Risks are high on the agenda in our society, to the extent that we might refer to the society as a risk society. Our society experiences emerging technologies, like nanotechnology. Different actors respond to this in a variety of ways. Among these are the consumers, an important, but neglected category of actors in this context. Arguably it is in our role as consumers we first encountered nanotechnology, in the form of nano-enabled products at the consumers market. What consumers think and do, reacting to the mixed messages about benefits and risks of nanotechnology, contributes to how the risk society (with regard to nanotechnology) is developed, and in that sense becomes operationalized. The theme of this thesis is not just the responses of consumers (and how others perceive these) to the introduction of nanotechnology, but also a case study of how the risk society can be operationalized.