Generation of VP5 deficient mutant of infectious bursal disease virus strain HZ2

Infectious bursal disease virus (IBDV) is one of the most significant viral pathogens in chickens[1]. It causes high mortality in young chickens and establishes an immunosuppression state by destroying the precursorsInfectious bursal disease virus (IBDV) …     

一株新耐冷菌SA-8降解有机磷农药的研究

从东北地区受农药长期污染的土壤中通过富集培养、分离筛选到一株甲基对硫磷高效降解菌SA-8,根据生理生化特征,初步鉴定为邻单胞菌Plesiomonas sp..菌株降解甲基对硫磷的最适温度和pH分别为20℃和7.0,在此条件下培养24h,降解率达93%;当温度位于10℃时,降解率也有66.2%;而在35℃时降解率仅为27.3%.这些结果表明SA-8是一株耐冷有机磷农药降解菌.     

Nurse plant theory and its application in ecological restoration in lower subtropics of China

Nurse plants are those that facilitate the growth and development of other plant species （target species） beneath their canopy because they offer benign microhabitats that are more favorable for seed germination and/or seedling recruitment than their surrounding environment. Nurse plants have been mainly used to restore vegetation in arid and sub-arid zones in recent years. Based on summarizing the definition of nurse plant and target plant, we review the nursing effect mechanisms, ecological factors that influence nursing effect, relationships between nurse plant and ecological restoration. This review also brings forward possible pairs of nurse and target species at lower subtropical areas. Furthermore, we provide the potential tendency in nurse plant research and application.     

Thermodynamics and density functional theory study of potassium dichromate interaction with galena

The adsorption heat and reaction rate constant of potassium dichromate on the surface of galena were studied. The results indicate that potassium dichromate tends to adsorption on the galena surface. The reaction order is only 0.08385, suggesting that the concentration of potassium dichromate has little influence on its adsorption on the galena surface. In addition, the simulation of CrO₄2? adsorption on the PbS (100) surface in the absence and presence of O₂ was carried out by density functional theory (DFT). The calculated results show that CrO₄2? species adsorb energetically at the Pb-S bond site, and the presence of O₂ can enhance this adsorption.     

Study of prostate biopsy robot system

A system for prostate biopsy with robot assistance was proposed. The system consists of Motoman robot, needle insertion mechanism, and control software. A experiment was held with this software, and it proved that the whole system is simple, reliable and good application.     

Direct hydrothermal synthesis and magnetic property of titanate nanotubes doped magnetic metal ions

Pure titanate nanotubes and titanate nanotubes doped with Fe3+/Ni2+/Mn2+ ions were synthesized by the hydrothermal method. In this process,titanate nanotubes were first prepared synchronously with doping Fe3+/Ni2+/Mn2+ ions. The morphology,structure,thermal stability and magnetic property of titanate nanotubes were characterized by X-ray diffraction (XRD),transmission electron microscope (TEM),and magnetic measurement. The titanate nanotubes transformed into the anatase titania nanocrystals,and further the mixture of anatase and rutile titania along with increasing temperature. The results indicate that the titanate nanotubes doped with Fe3+/Ni2+/Mn2+ ions are paramagnetic behaviors.     

Study on the optimization of the combined blown converter process in Chongqing Iron and Steel Company

The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model. The results show that the maximal stirring energy is provided to the bath at the top lance height of about 50-100 mm. When the top lance height is in the range of 90-110 mm, the splashing amount caused by the top jet can reach the maximal value. The appropriate operational parameters of Chongqing Iron and Steel Company (CISC) converter have been established that the top lance height is 1600-1760 mm and the bottom blowing flowrate is 240-480 Nm3/h in the primary phase of a heat, 1100-1300 mm and 160-200 Nm3/h in the second phase, and 1040-1120 mm and 200-350 Nm3/h in the end phase. Also, the trial shows that the metallurgical result of the studied blow pattern is better than that of the former pattern. At the starting 3-4 min of a heat, the strong splashing is eliminated.     

Kondo resonance in a single-molecule transistor

When an individual molecule, nanocrystal, nanotube or lithographically defined quantum dot is attached to metallic electrodes via tunnel barriers, electron transport is dominated by single-electron charging and energy-level quantization. As the coupling to the electrodes increases, higher-order tunnelling and correlated electron motion give rise to new phenomena, including the Kondo resonance. To date, all of the studies of Kondo phenomena in quantum dots have been performed on systems where precise control over the spin degrees of freedom is difficult. Molecules incorporating transition-metal atoms provide powerful new systems in this regard, because the spin and orbital degrees of freedom can be controlled through well-defined chemistry. Here we report the observation of the Kondo effect in single-molecule transistors, where an individual divanadium molecule serves as a spin impurity. We find that the Kondo resonance can be tuned reversibly using the gate voltage to alter the charge and spin state of the molecule. The resonance persists at temperatures up to 30 K and when the energy separation between the molecular state and the Fermi level of the metal exceeds 100 meV.     

Overview of the Alliance for Cellular Signaling

The Alliance for Cellular Signaling is a large-scale collaboration designed to answer global questions about signalling networks. Pathways will be studied intensively in two cells--B lymphocytes (the cells of the immune system) and cardiac myocytes--to facilitate quantitative modelling. One goal is to catalyse complementary research in individual laboratories; to facilitate this, all alliance data are freely available for use by the entire research community.     

Forced extension of P-selectin construct using steered molecular dynamics

P-selectin, a 70-nm-long cellular adhesive molecule, possesses elastic and extensible properties when neutrophils roll over the activated endotheliam of blood vessel in inflammatory reaction. Transient formation and dissociation of P-selectin/ligand bond on applied force of blood flow induces the extension of P-selectin and relevant ligands.Steered molecular dynamics simulations were performed to stretch a single P-selectin construct consisting of a lectin(Lec) domain and an epithelial growth factor (EGF)-Iike domain, where P-selectin construct was forced to extend in water with pulling velocities of 0.005-0.05 nm/ps and with constant forces of 1000--2500 pN respectively. Resulting force-extension profiles exhibited a dual-peak pattern on various velocities, while both plateaus and shoulders appeared in the extension-time profiles on various forces. The force or extension profiles along stretching pathways were correlated to the conformational changes, suggesting that the structural collapses of P-selectin Lec/EGF domains were mainly attributed to the burst of hydrogen bonds within the major β sheet of EGF domain and the disruptions of two hydrophobic cores of Lec domain. This work furthers the understanding of forced dissociation of P-selectin/ligand bond.