There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

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’

The statistical behavior of the sea clutter in synthetic aperture radar (SAR) images is characterized by both the marginal distribution and the spatial correlation. However, simultaneous modeling of the joint information remains a difficult job because of the non-Gaussian clutter nature. In this paper, a semiparametric approach is proposed for addressing this problem. First, we investigate the applicability of the nonparametric kernel density estimator (KDE) for estimating the marginal distribution of the SAR clutter and show that the KDE is most applicable in the log-intensity domain. Second, we propose to estimate the underlying spatial correlation structure with a copula approach and show that the Gaussian copula is a sufficiently accurate model. Consequently, the KDE, together with the Gaussian copula, offers a full characterization of the joint probability distribution, based on which a quadratic detector of null distribution governed by the well-known chi-squared law can be conveniently designed for constant false alarm rate detection. In the experiment, results with both simulated and real SAR data demonstrate that, compared with the single-point detector using only the marginal distribution, the proposed method, which incorporates spatial correlation, significantly improves the detection performance with regard to either the receiver-operating-characteristic curve or detected target pixels. The tradeoff, however, lies in a loss of false alarm rate control resulting from increased uncertainty in estimating higher dimensional distributions.

On Semiparametric Clutter Estimation for Ship Detection in Synthetic Aperture Radar Images

Cell-specific information on the quantity and localization of key mRNAs at single copy sensitivity in single cells is critical for evaluating basic cellular process, disease risk, and efficacy of therapy. Quantification of overexpressed mRNAs beyond the diffraction limit is constrained by the optical property of the probes and microscopy techniques. In this report, nanosized barium titanium oxide (BaTiO3, BTO) crystals were utilized as probes for mRNA quantification by a second harmonic super-resolution microscopy (SHaSM). The SHaSM was able to detect a single copy of the human epidermal growth factor receptor 2 (Her2) mRNA at a resolution of 55.6 nm with the ability to resolve multiple mRNA copies in a diffraction-limited spot. Her2 mRNA per cell was counted in SK-BR-3, MCF-7, and HeLa cell lines as 595 ± 79.1, 38.9 ± 8.26, and 1.5 ± 2.8, respectively. Our single-cell quantification results were validated with the fluorescence in situ hybridization studies and quantitative PCR, showing better specificity...

http://pubs.acs.org/doi/pdf/10.1021/nn505096t

Second Harmonic Super-resolution Microscopy for Quantification of mRNA at Single Copy Sensitivity

Nanoscale texturing has been studied for various applications, but most of the methods used to make these nanostructures are expensive and not easily scalable. Some of these methods require etching steps or high-temperature processes, which limit the processes to certain materials, such as silicon. In this study, we report a non-etching nanoscale texturing technique that allows for controlled oxidation to create tin oxide nanocones over large areas. Similar results are obtained on different substrates, such as silicon, aluminum foil, quartz, and polyimide film, and this method can be employed at temperatures as low as 220 °C in ambient pressure. This simple and scalable nanotexturing process improves the anti-reflection effect in photovoltaic devices. The light absorption of a polycrystalline silicon substrate, a widely used photovoltaic material, is increased by 30% over the wavelength range of 400–850 nm after fabricating nanocones on the surface.

Low-temperature self-catalytic growth of tin oxide nanocones over large areas.

A variety of methods, devices, systems and arrangements are implemented involving nanowire meshes. One such method is implemented to include synthesizing metal nanowires in a solution containing a structure-directing agent. The metal nanowires are deposited on a substrate to form a sheet of nanowires. The deposited metal nanowires are heated to a temperature less than about 200 degrees Celsius and for a period of time of about 10 minutes to 60 minutes, thereby removing the structure-directing agent and modifying the electrical conductivity and optical transmittance of the sheet of nanowires.

Systems, Methods, Devices and Arrangements For Nanowire Meshes

As consistent with various embodiments, an electronic device includes a carbon nanotube film having a plurality of carbon nanotubes. In certain embodiments, a coating, such as an inorganic coating, is formed on a surface of carbon nanotube. The nanotube film supports the device and facilitates electrical conduction therein. The coated nanotube is amenable to implementation with devices such as thin film batteries, a battery separator, thin film solar cells and high-energy Lithium ion batteries.

Yi Cui

Papers

On Semiparametric Clutter Estimation for Ship Detection in Synthetic Aperture Radar Images

Second Harmonic Super-resolution Microscopy for Quantification of mRNA at Single Copy Sensitivity

Low-temperature self-catalytic growth of tin oxide nanocones over large areas.

Systems, Methods, Devices and Arrangements For Nanowire Meshes

Nanotube-based nanomaterial membrane