Peidong Yang

Bio: Peidong Yang is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: Nanowire & Perovskite (structure). The author has an hindex of 183, co-authored 562 publications receiving 144351 citations. Previous affiliations of Peidong Yang include Max Planck Society & University of California, Santa Barbara.

Single Nanowire Lasers.

Abstract: Ultraviolet lasing from single zinc oxide nanowires is demonstrated at room temperature. Near-field optical microscopy images quantify the localization and the divergence of the laser beam. The linewidths, wavelengths, and power dependence of the nanowire emission characterize the nanowire as an active optical cavity. These individual nanolasers could serve as miniaturized light sources for microanalysis, information storage, and optical computing.

Observation of a pp̄ mass threshold enhancement in Ψ′ π +π - J/Ψ(J/Ψ γ p) decay

Abstract: The decay channel Ψ' → π+π− J/Ψ(J/Ψ → γp) is studied using a sample of 1.06 × 108 Ψ' events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the p invariant mass spectrum. The enhancement can be fitted with an S-wave Breit–Wigner resonance function with a resulting peak mass of M = 1861+6−13 (stat)+7−26 (syst) MeV/c2 and a narrow width that is Γ < 38 MeV/c2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with well established mesons.

Characterization of heat transfer along a silicon nanowire using thermoreflectance technique

Abstract: We studied heat transfer along a silicon nanowire suspended between two thin-film heaters using a thermoreflectance imaging technique. The thermoreflectance imaging system achieved submicrometer spatial resolution and 0.1/spl deg/C temperature resolution using visible light. The temperature difference across the nanowire was measured, and then its thermal resistance was calculated. Knowing the dimension of the nanowire (115 nm in width and 3.9 /spl mu/m in length), we calculated the thermal conductivity of the sample, which is 46 W/mK. Thermal conductivity decreases with decreasing wire size. For a 115-nm-wide silicon nanowire, the thermal conductivity is only one-third of the bulk value. In addition, the transient response of the thin-film heaters was also examined using three-dimensional thermal models by the ANSYS program. The simulated thermal map matches well with the experimental thermoreflectance results.

Silencing of EphA2 inhibits invasion of human gastric cancer SGC-7901 cells in vitro and in vivo.

Abstract: Receptor tyrosine kinases (RTKs), the common products of transforming oncogenes, have been widely used as indicators in the genesis and progression of human tumors. Until now, the erythropoietin-producing human hepatocellular (Eph) receptors have been recognized as the largest family of RTKs. EphA2, one member of Eph receptors, locates on human chromosome 1p36.1 which is a hot region for cancer research. It has been reported that high EphA2 expression levels were correlated with the tumor metastasis and poor prognosis. Increased expression of EphA2 can promote tumor growth and enhance the metastatic potential. To further define the function of EphA2 in malignant invasion, we employed the small interference RNA (siRNA) technique to knockdown gene expression of EphA2 in the gastric cancer SGC-7901 cell. Our results showed that the expression of double stranded RNA led to the efficient and specific inhibition of endogenous EphA2 expression in SGC-7901 cells. Silencing of EphA2 expression inhibited cell proliferation, caused cell cycle arrest, and decreased cell invasion in vitro. In addition, intratumoral injection EphA2 siRNA plasmid suppressed the growth of SGC-7901 cells xenografts in nude mice. Furthermore, knockdown of EphA2 expression reduced the expression of matrix metalloproteinase-9 (MMP-9) in vitro and in vivo. In conclusion, our findings demonstrate that silencing of EphA2 inhibits gastric cancer SGC-7901 cell proliferation, invasion and MMP-9 expression, which indicate that the specific inhibition of EphA2 may be a potential approach for gastric cancer therapy.

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。

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

A comprehensive review of zno materials and devices

Abstract: The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high-quality substrates and reports of p-type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935)], studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966)], detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954)], and its growth by chemical-vapor transport in 1970 by Galli and Coker [Appl. Phys. ...