抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Freedom of design, mass customisation, waste minimisation and the ability to manufacture complex structures, as well as fast prototyping, are the main benefits of additive manufacturing (AM) or 3D printing. A comprehensive review of the main 3D printing methods, materials and their development in trending applications was carried out. In particular, the revolutionary applications of AM in biomedical, aerospace, buildings and protective structures were discussed. The current state of materials development, including metal alloys, polymer composites, ceramics and concrete, was presented. In addition, this paper discussed the main processing challenges with void formation, anisotropic behaviour, the limitation of computer design and layer-by-layer appearance. Overall, this paper gives an overview of 3D printing, including a survey on its benefits and drawbacks as a benchmark for future research and development.

Additive manufacturing (3D printing): A review of materials, methods, applications and challenges

Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Coinage metals, such as Au, Ag, and Cu, have been important materials throughout history.1 While in ancient cultures they were admired primarily for their ability to reflect light, their applications have become far more sophisticated with our increased understanding and control of the atomic world. Today, these metals are widely used in electronics, catalysis, and as structural materials, but when they are fashioned into structures with nanometer-sized dimensions, they also become enablers for a completely different set of applications that involve light. These new applications go far beyond merely reflecting light, and have renewed our interest in maneuvering the interactions between metals and light in a field known as plasmonics.2–6

In plasmonics, the metal nanostructures can serve as antennas to convert light into localized electric fields (E-fields) or as waveguides to route light to desired locations with nanometer precision. These applications are made possible through a strong interaction between incident light and free electrons in the nanostructures. With a tight control over the nanostructures in terms of size and shape, light can be effectively manipulated and controlled with unprecedented accuracy.3,7 While many new technologies stand to be realized from plasmonics, with notable examples including superlenses,8 invisible cloaks,9 and quantum computing,10,11 conventional technologies like microprocessors and photovoltaic devices could also be made significantly faster and more efficient with the integration of plasmonic nanostructures.12–15 Of the metals, Ag has probably played the most important role in the development of plasmonics, and its unique properties make it well-suited for most of the next-generation plasmonic technologies.16–18

1.1. What is Plasmonics?
Plasmonics is related to the localization, guiding, and manipulation of electromagnetic waves beyond the diffraction limit and down to the nanometer length scale.4,6 The key component of plasmonics is a metal, because it supports surface plasmon polariton modes (indicated as surface plasmons or SPs throughout this review), which are electromagnetic waves coupled to the collective oscillations of free electrons in the metal.

While there are a rich variety of plasmonic metal nanostructures, they can be differentiated based on the plasmonic modes they support: localized surface plasmons (LSPs) or propagating surface plasmons (PSPs).5,19 In LSPs, the time-varying electric field associated with the light (Eo) exerts a force on the gas of negatively charged electrons in the conduction band of the metal and drives them to oscillate collectively. At a certain excitation frequency (w), this oscillation will be in resonance with the incident light, resulting in a strong oscillation of the surface electrons, commonly known as a localized surface plasmon resonance (LSPR) mode.20 This phenomenon is illustrated in Figure 1A. Structures that support LSPRs experience a uniform Eo when excited by light as their dimensions are much smaller than the wavelength of the light.



Figure 1

Schematic illustration of the two types of plasmonic nanostructures discussed in this article as excited by the electric field (Eo) of incident light with wavevector (k). In (A) the nanostructure is smaller than the wavelength of light and the free electrons ...



In contrast, PSPs are supported by structures that have at least one dimension that approaches the excitation wavelength, as shown in Figure 1B.4 In this case, the Eo is not uniform across the structure and other effects must be considered. In such a structure, like a nanowire for example, SPs propagate back and forth between the ends of the structure. This can be described as a Fabry-Perot resonator with resonance condition l=nλsp, where l is the length of the nanowire, n is an integer, and λsp is the wavelength of the PSP mode.21,22 Reflection from the ends of the structure must also be considered, which can change the phase and resonant length. Propagation lengths can be in the tens of micrometers (for nanowires) and the PSP waves can be manipulated by controlling the geometrical parameters of the structure.23

/pdf/controlling-the-synthesis-and-assembly-of-silver-1ktlgomyt6.pdf

Controlling the synthesis and assembly of silver nanostructures for plasmonic applications

Superhydrophobic self-cleaning surfaces are based on the surface micro/nanomorphologies; however, such surfaces are mechanically weak and stop functioning when exposed to oil. We have created an ethanolic suspension of perfluorosilane-coated titanium dioxide nanoparticles that forms a paint that can be sprayed, dipped, or extruded onto both hard and soft materials to create a self-cleaning surface that functions even upon emersion in oil. Commercial adhesives were used to bond the paint to various substrates and promote robustness. These surfaces maintained their water repellency after finger-wipe, knife-scratch, and even 40 abrasion cycles with sandpaper. The formulations developed can be used on clothes, paper, glass, and steel for a myriad of self-cleaning applications.

http://science.sciencemag.org/content/sci/347/6226/1132.full.pdf

Robust self-cleaning surfaces that function when exposed to either air or oil

La presente invention concerne une strategie pour creer une surface glissante poreuse impregnee de liquides (SLIPS) et auto-reparatrice. Des surfaces râpeuses (a savoir poreuses) peuvent s'utiliser pour garder en place un liquide lubrifiant designe ici Liquide B afin de repousser une vaste gamme de materiaux designees par Objet A (A solide ou A liquide). SLIPS depasse les autres surfaces traditionnelle en termes de capacite de repousser divers liquides simples ou complexes (eau, hydrocarbure, petrole buret ou sang), de garder une hysteresis de contact a angle faible (<2,5°), de retrouver rapidement sa capacite de repousser les liquides apres l'endommagement (dans les 0,1-1 s), de resister au gel a l'adherence des micro-organismes et des insectes et de fonctionner a des pressions eleves (jusqu'a au moins 690 atm). Certaines applications d'exemple dans lesquelles SLIPS pourrait etre utile comprennent la manipulation et le transport de fluides efficaces en termes d'energie, la detection optique et la medecine, ainsi comme des materiaux autonettoyants et antisalissants fonctionnant dans des environnements extremes.

Surfaces glissantes à stabilité élevée à la pression possédant des caractéristiques de transparence optique et auto-réparatrices

Natural structural materials, such as bone and wood, can autonomously adapt their mechanical properties in response to loading to prevent failure. They smartly control the addition of material in locations of high stress by utilizing locally available resources guided by biological signals. On the contrary, synthetic structural materials have unchanging mechanical properties limiting their mechanical performance and service life. Here, a material system that autonomously adapts its mechanical properties in response to mechanical loading is reported inspired by the mineralization process of bone. It is observed that charges from piezoelectric scaffolds can induce mineralization from media with mineral ions. The material system adapts to mechanical loading by inducing mineral deposition in proportion to the magnitude of the loading and the resulting piezoelectric charges. Moreover, the mechanism allows a simple one-step route for making graded materials by controlling stress distribution along the scaffold. The findings can pave the way for a new class of self-adaptive materials that reinforce the region of high stress or induce deposition of minerals on the damaged areas from the increase in stress to prevent/mitigate failure. They can also contribute to addressing the current challenges of synthetic materials for load-bearing applications from self-adaptive capabilities.

Bioinspired Materials with Self-Adaptable Mechanical Properties

Provided are compositions (which may inks), methods, devices, and systems that are used with 3D printing. The compositions contain fluoropolymer particles, one or more type of a medium, one or more surfactants, and one or more shear thinning agents. The fluoropolymer component can be one or more of polytetrafluoroethylene (PTFE), perfluoroalkoxy, fluorinated ethylene-propylene, and poly ethyl enetetrafluoroethylene. Cartridges that contain the compositions are also provided. Methods of making the compositions, methods of using the compositions for 3D printing, and articles of manufacture, such as medical devices, are also provided.

Fluoropolymer shear-thinning inks and methods of making and using same

We demonstrate the fabrication of plasmonic nanostructures (rings, split rings, and other structures) by a process involving molding by soft lithography, thin film deposition, and mechanical sectioning (nanoskiving). This unique process is highly parallelizable and allows for the fabrication of nanostructures of multiple materials in the same plane and very high aspect ratio structures. We characterize the optical properties of concentric gold rings fabricated by this process in the near- to mid-infrared by FDTD simulations and FTIR spectroscopy.

Sung Hoon Kang

Papers

Surfaces glissantes à stabilité élevée à la pression possédant des caractéristiques de transparence optique et auto-réparatrices

Bioinspired Materials with Self-Adaptable Mechanical Properties

Fluoropolymer shear-thinning inks and methods of making and using same

Large area multi-material plasmonic nanostructures fabricated by replica molding and mechanical sectioning

A Novel Sutureless Anastomotic Device in a Swine Model: A Proof of Concept Study.