Enhancement production of qinlingmycin by a soilderived Streptomyces No. 24 using protoplast fusion technology and assessment of antibacterial activity

This study was aimed at improving qinlingmycin production by protoplast fusion technology for Streptomyces No. 24 and mutant strain Ms-24. In the protoplast preparation, the optimal glycine concentration, lysozyme concentration and lytic time were 0.25%, 1 mg/ml and 1 h, respectively. In the process of protoplast fusion, the weight of polyethylene glycol (PEG) molecule had little effect, while the top fusion efficiency was observed at 50% PEG. By protoplast fusion, the three high qinlingmycin producing fusants Pf77, pf126 and pf138 were fortunately obtained from 163 fusant strains. In vitro antibacterial activities of the three fusants than Streptomyces No. 24 were increased by 43.48, 60.87 and 65.22%, respectively. The results by HPLC detection analysis showed qinlingmycin productions of the fusants fermented broths were increased by 36.59, 74.39 and 91.46%, respectively, than that of Streptomyces No. 24. The fusants showed good heredity stability in continuing transferred ten generations test.Key words: Protoplast fusion, Streptomyces No. 24, mutant Ms-24, qinlingmycin, antibacterial activit

Spin injection from the Heusler alloy Co_2MnGe into Al_0.1Ga_0.9As/GaAs heterostructures

Electrical spin injection from the Heusler alloy Co_2MnGe into a p-i-n Al_0.1Ga_0.9As/GaAs light emitting diode is demonstrated. A maximum steady-state spin polarization of approximately 13% at 2 K is measured in two types of heterostructures. The injected spin polarization at 2 K is calculated to be 27% based on a calibration of the spin detector using Hanle effect measurements. Although the dependence on electrical bias conditions is qualitatively similar to Fe-based spin injection devices of the same design, the spin polarization injected from Co_2MnGe decays more rapidly with increasing temperature.Comment: 8 pages, 4 figure

Does afforestation deteriorate haze pollution in Beijing-Tianjin-Hebei (BTH), China?

Although aggressive emission control strategies have been implemented recently in the Beijing-Tianjin-Hebei area (BTH), China, pervasive and persistent haze still frequently engulfs the region during wintertime. Afforestation in BTH, primarily concentrated in the Taihang and Yan Mountains, has constituted one of the controversial factors exacerbating the haze pollution due to its slowdown of the surface wind speed. We report here an increasing trend of forest cover in BTH during 2001-2013 based on long-term satellite measurements and the impact of the afforestation on the fine-particle (PM2.5) level. Simulations using the Weather Research and Forecast model with chemistry reveal that afforestation in BTH since 2001 has generally been deteriorating the haze pollution in BTH to some degree, enhancing PM2.5 concentrations by up to 6% on average. Complete afforestation or deforestation in the Taihang and Yan Mountains would increase or decrease the PM2.5 level within 15% in BTH. Our model results also suggest that implementing a large ventilation corridor system would not be effective or beneficial to mitigate the haze pollution in Beijing

Elliptic flow of ϕ\phi meson and strange quark collectivity at RHIC

Based on A Multi-Phase Transport (AMPT) model, we have studied the elliptic flow $v_{2}$ of $\phi$ mesons from reconstructed $K^{+}K^{-}$ decay channel at the top Relativistic Heavy Ion Collider energy at Brookhaven National Laboratory. The dependences of $v_{2}$ on transverse momentum $p_T$ and collision centrality are presented and the rescattering effect of $\phi$ mesons in the hadronic phase is also investigated. The results show that experimental measurement of $v_{2}$ for $\phi$ mesons can retain the early collision information before $\phi$ decays and that the $\phi$ $v_2$ value obeys the constituent quark number scaling which has been observed for other mesons and baryons. Our study indicates that the $\phi$ $v_2$ mostly reflects partonic level collectivity developed during the early stage of the nucleus-nucleus collision and the strange and light up/down quarks have developed similar angular anistropy properties at the hadronization.Comment: 5 pages and 5 figures; accepted by Physical Review

Integrated genomic approaches identify major pathways and upstream regulators in late onset Alzheimer's disease.

Previous studies have evaluated gene expression in Alzheimer's disease (AD) brains to identify mechanistic processes, but have been limited by the size of the datasets studied. Here we have implemented a novel meta-analysis approach to identify differentially expressed genes (DEGs) in published datasets comprising 450 late onset AD (LOAD) brains and 212 controls. We found 3124 DEGs, many of which were highly correlated with Braak stage and cerebral atrophy. Pathway Analysis revealed the most perturbed pathways to be (a) nitric oxide and reactive oxygen species in macrophages (NOROS), (b) NFkB and (c) mitochondrial dysfunction. NOROS was also up-regulated, and mitochondrial dysfunction down-regulated, in healthy ageing subjects. Upstream regulator analysis predicted the TLR4 ligands, STAT3 and NFKBIA, for activated pathways and RICTOR for mitochondrial genes. Protein-protein interaction network analysis emphasised the role of NFKB; identified a key interaction of CLU with complement; and linked TYROBP, TREM2 and DOK3 to modulation of LPS signalling through TLR4 and to phosphatidylinositol metabolism. We suggest that NEUROD6, ZCCHC17, PPEF1 and MANBAL are potentially implicated in LOAD, with predicted links to calcium signalling and protein mannosylation. Our study demonstrates a highly injurious combination of TLR4-mediated NFKB signalling, NOROS inflammatory pathway activation, and mitochondrial dysfunction in LOAD