3H的辐射生物学效应的研究 Ⅲ:3H-Thymidine 诱发水棉(Spirogyra SP.)产 生微核仁的电子显微镜观察

结果显示,水绵细胞分裂间期的核仁为近球形,由核仁颗粒区和立体网状的核仁纤维区组成。水绵在含有10uci/ml的3H-Thymidine培养基培养1400h后,受到细胞内外,细胞核内外3H的 辐射作用,分裂间期核仁增大,核仁中小部分纤能区或颗粒区的物质成团离开核仁,在核中,核仁旁形成"微核仁"。这种微核仁与通常用普通显微镜观察到 的"微核不同"。图3参15

Rana grylio virus thymidine kinase gene: an early gene of iridovirus encoding for a cytoplasmic protein

The presence of thymidine kinase (TK) is a feature of many large DNA viruses. Here, a TK gene homologue was cloned and characterized from Rana grylio virus (RGV), a member of family Iridoviridae. RGV TK encodes a protein of 195 aa with a predicted molecular mass of 22.1 kDa. Homologues of the protein were present in all the currently sequenced iridoviruses, and phylogenetic analysis showed that it was much close to cellular TK type 2 (TK2), deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK). Subsequently, Western blotting revealed TK expression increased with time from 6 h post-infection in RGV-infected cells. Using drug inhibition analysis by protein synthesis inhibitor (cycloheximide) and DNA replication inhibitor (cytosine arabinofuranoside), RGV TK was classified as the early expression gene during in vitro infection. Subcellular localization by TK-GFP fusion protein expression and immunofluorescence staining showed RGV TK was an exclusively cytoplasmic protein in fish cells. Collectively, current data indicate that RGV TK was an early gene of iridovirus which encoded a cytoplasmic protein in fish cells.

Experimental Investigation on Propane Hydrate Dissociation by High Concentration Methanol and Ethylene Glycol Solution Injection

The dissociation behaviors of propane hydrate by high concentration alcohols inhibitors injection were investigated. Methanol (30.0, 60.1, 80.2, and 99.5 wt %) and ethylene glycol (30.0, 60.1, 69.8, 80.2, and 99.5 wt %) solution were injected, respectively, as alcohols inhibitors in 3.5 L transparent reactor. It is shown that the average dissociation rates of propane hydrate injecting methanol and ethylene glycol solution are 0.02059-0.04535 and 0.0302-0.0606 mol.min(-1).L-1, respectively. The average dissociation rates increase with the mass concentration increase of alcohols solution, and it is the biggest when 99.5 wt % ethylene glycol solution was injected. The presence of alcohols accelerates gas hydrate dissociation and reduces the total need of external energy to dissociate the hydrates. Density differences act as driving force, causing the acceleration effects of ethylene glycol on dissociation behaviors of propane hydrate are better than that of methanol with the same injecting flux and mass concentration.

Experimental investigation of production behavior of methane hydrate under ethylene glycol injection in unconsolidated sediment

This article investigates the gas production behavior from methane hydrate (MH) in porous sediment by injecting ethylene glycol (EG) solution with the different concentrations and the different injection rates in an one-dimensional experimental apparatus. The results suggest that the gas production process can be divided into the four stages: (1) the initial injection, (2) the EG diluteness, (3) the hydrate dissociation, and (4) the remained gas output. Nevertheless, the water production rate keeps nearly constant during the whole production process. The production efficiency is affected by both the EG concentration and the EG injection rate, and it reaches a maximum with the EG concentration of 60 wt %.

On the chemical synthesis and drug delivery response of folate receptor-activated, polyethylene glycol-functionalized magnetite nanoparticles

We describe here the chemical synthesis and in vitro drug delivery response of polyethylene glycol (PEG)-functionalized magnetite (Fe3O4) nanoparticles, which were activated with a stable ligand, folic acid, and conjugated with an anticancer drug, doxorubicin. The functionalization and conjugation steps in the chemical synthesis were confirmed using Fourier transform infrared spectroscopy. The drug-release behavior of PEG-functionalized and folic acid-doxorubicin-conjugated magnetic nanoparticles was characterized by two stages involving an initial rapid release, followed by a controlled release. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Biodegradable Interpolyelectrolyte Complexes Based on Methoxy Poly(ethylene glycol)-b-poly(alpha,L-glutamic acid) and Chitosan

We synthesized methoxy poly(ethylene glycol)-b-poly(alpha,L-glutamic acid) (mPEGGA) diblock copolymer by ring-opening polymerization of N-carboxy anhydride of gamma-benzyl-L-glutamate (NCA) using amino-terminated methoxy polyethylene glycol (mPEG) as macroinitiator. Polyelectrolyte complexation between mPEGGA as neutral-block-polyanion and chitosan (CS) as polycation has been scrutinized in aqueous solution as well as in the solid state.