Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

Fabrication and Characterization of Chirped 3D Photonic Crystals

Light-absorbing materials can exhibit exceptional photothermal effects as their characteristic dimensions approach the nanoscale. A flash welding technique that exploits the peculiar photothermal response of polyaniline nanofibres opens new avenues for processing and patterning polymer-based materials and devices.

Welding and patterning in a flash

Oxidative etching is a powerful tool for carving out new designs in metal nanocrystals. In this issue of ACS Nano, Jin et al. demonstrate how this tool can be applied to the fabrication of Pd nanoframes by carefully balancing the rates of etching and growth during the excavation of solid nanocrystals. In this Perspective, we offer a brief overview on the evolution of oxidative etching as an alternative route to the facile synthesis of well-controlled metal nanocrystals, as well as an outlook into the future directions of the field.

The Science and Art of Carving Metal Nanocrystals

http://oilab.seas.wustl.edu/epub/2013/CaiX_2013_Materials%20Today_v16_p67.pdf

Photoacoustic Microscopy in Tissue Engineering.

Herein we describe a protocol that generates Au icosahedra in high yields by simply mixing aqueous solutions of HAuCl 4 and N-vinyl pyrrolidone. Our mechanistic study reveals that water plays an important role in this synthesis: as a nucleophile, it attacks the gold-vinyl complex, leading to the production of an alcohol-based Au I intermediate. This intermediate then undergoes a redox reaction in which Au I is reduced to Au 0 , leading to the formation of Au atoms and then Au icosahedra of about 18 nm in size at a yield of 94 %, together with a carboxylic acid in the final product. This new protocol has also been employed to prepare multiply twinned nanoparticles of Ag (15-20 nm in size), spherical aggregates (25-30 nm in size) of Pd nanoparticles, and very small nanoparticles of Pt (2 nm in size). Since no organic solvent, surfactant, or polymer stabilizer is needed for all these syntheses, this protocol may provide a simple, versatile, and environmentally benign route to noble-metal nanoparticles having various compositions and morphologies.

Younan Xia

Papers

Fabrication and Characterization of Chirped 3D Photonic Crystals

Welding and patterning in a flash

The Science and Art of Carving Metal Nanocrystals

Photoacoustic Microscopy in Tissue Engineering.

Facile Synthesis of Gold Icosahedra in an Aqueous Solution by Reacting HAuCl4 with N‐Vinyl Pyrrolidone