Younan Xia

Bio: Younan Xia is an academic researcher from The Wallace H. Coulter Department of Biomedical Engineering. The author has contributed to research in topics: Nanocages & Nanowire. The author has an hindex of 216, co-authored 943 publications receiving 175757 citations. Previous affiliations of Younan Xia include Washington University in St. Louis & University of Texas at Dallas.

Some Recent Developments in the Chemical Synthesis of Inorganic Nanotubes

Abstract: Inorganic nanotubes have been a subject of intensive research in the past decade. We recently developed a number of synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. It is the intention of this contribution to provide a brief account of these research activities.

Metal Nanowires Synthesized by Solution-Phase Methods

Abstract: One-dimensional (1D) nanostructures (such as wires, rods, belts and tubes) have been a subject of intensive research due to their unique applications in fabricating nanoscale electronic, photonic, electrochemical, electromechanical, and sensing devices [1–8]. Nanowires with uniform diameters also represent an ideal model system to investigate the dependence of transport and optical properties on size confinement or reduction [9]. In addition, there are many other areas where nanowires could be exploited to significantly enhance the functionality or performance of a material; typical examples include catalysis, formation of superstrong and tough composites, and fabrication of specialized scanning probes [10]. As a result, a tremendous amount of effort has recently been devoted to the synthesis, characterization, and utilization of nanowires with well-controlled dimensions and properties [11–13].

A Tribute to Professor Buddy Ratner

Abstract: report the use of angle-dependent X-ray photoelectron spectroscopy (ADXPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to characterize the surfaces of four biodegradable materials based on poly(peptide-urethaneurea) block copolymers (2100894). The copolymers contain three different blocks: the soft block made of poly(caprolactone diol) (PCL), the hard block consisting of lysine diisocyanate with a hydrazine chain extender, and the oligopeptide block containing proline, hydroxyproline, and glycine. The incorporation of oligopeptide block into the polyurethane back-bone is known to result in synthetic polymers with controllable biodegradation profiles. Their results indicate that the surfaces of all four polymers tested are enriched with PCL (i.e., the most hydrophobic component of the three blocks), shedding light on the biodegradation behaviors of these polymers. Stephanie J. Bryant and coworkers mapped macrophage polarization and origin during the

Fast parallel algorithms for short-range molecular dynamics

Abstract: 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.

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

Abstract: 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。

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

Abstract: 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