Discharge of treated Fukushima nuclear accident contaminated water: macroscopic and microscopic simulations.

The diffusion process of the treated Fukushima nuclear accident contaminated water to be discharged into the Pacific Ocean from 2023 is analyzed by two analysis models from macroscopic and microscopic perspectives. Results show that the tritium will spread to the whole North Pacific in 1200 days, which is important to formulate global coping strategies.

Cytochrome C catalyzed oxygen tolerant atom-transfer radical polymerization.

Atom-transfer radical polymerization (ATRP) is a well-known technique for controlled polymer synthesis. However, the ATRP usually employed toxic heavy metal ionas as the catalyst and was susceptible to molecular oxygen, which made it should be conducted under strictly anoxic condition. Conducting ATRP under ambient and biocompatible conditions is the major challenge. In this study, cytochrome C was explored as an efficient biocatalyst for ATRP under biocompatible conditions. The cytochrome C catalyzed ATRP showed a relatively low polymer dispersity index of 1.19. More interestingly, the cytochrome C catalyzed ATRP showed superior oxygen resistance as it could be performed under aerobic conditions with high dissolved oxygen level. Further analysis suggested that the Fe(II) embed in the cytochrome C might serve as the catalytic center and methyl radical was responsible for the ATRP catalysis. This work explored new biocompatible catalyst for aerobic ATRP, which might open new dimension for practical ATRP and application of cytochrome C protein.

[Size distribution and characterization of EC and OC in aerosols during the Olympics of Beijing, China].

Samples of airborne PM with different size were collected by cascade impactor (Andersen) in Beijing during the Beijing Olympics. Organic carbon (OC) and elemental carbon (EC) in particles were determined by DRI Model 2001 A t carbon analyzer of USA. PM (56%), OC (55%) and EC (73%) were associated with the fine particle below 2.1 microm. OC and EC account for 25% and 5% of particle below 2.1 microm, respectively, which indicates that carbonaceous aerosols are key components for controlling fine particles pollution in Beijing. It is found that Beijing auto measures were effective in abatement of carbonaceous aerosols. The ratios of OC/EC indicated that the main origins of carbonaceous aerosols in fine particle were automobile exhaust fumes and coal combustion and in coarse particle were biomass burning and cooking. The average percentage of estimated secondary OC (OC(sec)) in the total OC (OC(tot)) in TSP was 74%. The results of correlation analysis show that the correlation coefficient between the OC and secondary water soluble ions (SO4(2-), NO3-, NH4+, NO2-) were very high in PM2.1 (R2 = 0.88), while the correlation coefficient was very faint in particles greater than 2.1 microm (R2 = 0.21).

Important effects of lithium carbonate on stoichiometry and property of the inclusion complexes of polypropylene glycol and ß-cyclodextrin.

The present work reveals a significant influence of lithium carbonate (Li(2)CO(3)) on stoichiometry, yield, spectral property, and thermal behavior of the inclusion complex formed by polypropylene glycol (PPG) and ß-cyclodextrin (CD). First, the presence of Li(2)CO(3) in aqueous solution leads to the formation of an inclusion complex PPG-(ß-CD)(6), which is completely different from that precipitated from pure water. This finding is supported by the result of a similar experiment in the case of lithium chloride, demonstrating that the self-assembling behavior of PPG, a flexible oligomer, and ß-CD, a rigid oligomer, in solution can be mediated by additions of the lithium salts. Second, powder X-ray diffraction patterns indicate that the lithium salts in solution play a considerable role in fabricating three-dimensional structures of the complex. Third, the difference in stoichiometry and microstructure of the complexes precipitated from different media is reflected by the difference of their thermal properties. Finally, the results of viscosity, surface tension, and conductivity measurements provide positive support on the effect of the lithium salts on the physical property of PPG solution. Taken together, these observations provide a novel framework for understanding functions of inorganic salts in designing and constructing supramolecules.

Formation, characterization, and thermal degradation behavior of a novel tricomponent aggregate of beta-cyclodextrin, ferrocene, and polypropylene glycol.

A tricomponent aggregate PPG-Fc-beta-CD formed by polypropylene glycol (PPG), ferrocene (Fc), and beta-cyclodextrin (beta-CD) was obtained and characterized by a series of physical methods, such as (1)H nuclear magnetic resonance, flame atomic absorption spectrometry, high performance liquid chromatography, UV-vis absorption spectroscopy, thermogravimetry, and gas chromatography coupled to time-of-flight mass spectrometry. First, the tricomponent aggregate exhibited a component ratio of 1:28:32 (PPG/Fc/beta-CD) in the solid state, and showed a completely different order in thermal stability when compared with beta-CD: under a nitrogen atmosphere, beta-CD > PPG-Fc-beta-CD, and in a vacuum, PPG-Fc-beta-CD > beta-CD. Second, the appearance of two peculiar points p and q at the end of TG curve of the aggregate gave a strong impression that the degradation rate further increased after the sharp decomposition of the aggregate reached point p and the amount present in the residual fraction at point q about 780.0 K was lower than 1%, both of which were rather different from those reported previously. This finding implied that the molecular assembly resulting from the binding interaction among Fc, PPG, and beta-CD induced more efficiently the degradation of each of them. Third, an interesting phenomenon was found that the order of thermal release of the three assembled components in PPG-Fc-beta-CD was Fc > beta-CD > PPG. Results of this study provide some insight into an initial attempt to construct a supramolecule among a polymer, a coordination compound, and an organic compound.

[Pollution characteristics of n-alkanes in atmospheric fine particles during Spring Festival of 2007 in Beijing].

Research PM2.5 aerosols had been carried out with sampler of high-volume sampler during Spring Festival of 2007 in Beijing, and the concentrations of n-alkane in PM2.5 samples were determined via GC-MS. The average concentrations of PM2.5 which were all exceeded WHO threshold values were higher in the night than those in the day time. The n-alkane homolog from C10 to C33 were detected with the major peak carbon numbers ranging from 23 to 25. The total concentrations of n-alkane were higher in the night (943.5 ng x m(-3)) than those in the day time (581.1 ng x m(-3)). And also we found that the average concentrations of n-allkane before New Year's Eve (1,025.5 ng x m(-3)) were higher than those after (536.6 ng x m(-3)). The CPI values were 0.9-1.4 with average of 1.15. Those results may mean that primary resource of n-alkane in fine particles was the incomplete combustion of fossil fuel. The percent contribution of leaf "Wax" n-alkane indicated that about 8.5%-47% of n-alkane came from waxy leaf surface abrasion.

[Pollution characteristic of PAHs in atmospheric particles during the Spring Festival of 2007 in Beijing].

Research on PM10, and PM2.5, aerosols had been carried out with sampler of large flow capacity during the Spring Festival of 2007 in Beijing, and the concentration of polycyclic aromatic hydrocarbons (PAHs) in PM2.5, samples were determined via GC-MS. The average concentrations of aerosols are higher in the night (PM10: 232 microg x m(-3); PM2.5: 132 microg x m(-3)) than those in the day time (PM10: 194 microg x m(-3); PM2.5: 107 microg x m(-3)). The average concentrations are higher after the new year's eve (PM10: 252.3 microg x m(-3), PM2.5: 123.8 microg x m(-3)) compared with those before (PM10: 166.7 microg x m(-3), PM2.5: 106.8 microg x m(-3)). And we also find that the concentration of PAHs in PM2.5 aerosols is generally higher in the night (106.4 ng x m(-3)) than that in the day time (44.2 ng x m(-3)), and the total concentration of 17 PAHs before new year's eve (95.9 ng x m(-3)) is higher than that after (58.9 ng x m(-1)). Those results may mean that the aerosols are influenced by burning of fireworks in addition to be subjected to the meteorological condition. At the same time, there is little influence of playing fireworks on the PAHs concentration, and the changes of the concentration of PAHs can be explained by the decrease of industrial and vehicular transportation pollutant during the Festival period. It can be judged by the characteristic ratio such as Fuloranthene/pyrene that the primary resource of PAHs in particles is the combustion of coal, and the combustion of gasoline is in the next place.

A comparative study on the binding behaviors of beta-cyclodextrin and its two derivatives to four fanlike organic guests.

Four fanlike organic compounds, 1-ethoxybenzene (EOB), 1-butoxybenzene (BOB), 1-dodecyloxybenzene (DOB), and 1-(dodecyloxy)-2-methoxybenzene (DOMB), were chosen as guests, and beta-cyclodextrin (beta-CD) and its two derivatives, mono(2-O-2-methyl)-beta-CD and mono(2-O-2-hydroxy-propyl)-beta-CD, were chosen as hosts. Energy changes involved in host-guest inclusion processes were clearly obtained by applying semiempirical PM3 calculations. According to this, probable structures of the host-guest inclusion complexes were proposed. The inclusion systems in aqueous solution were investigated by UV-vis spectroscopy and nuclear magnetic resonance ((1)H NMR) titration, and the formation constants (K) of the inclusion complexes were determined using the Benesi-Hildebrand equation. Moreover, two solid inclusion complexes of beta-CD with EOB and DOB were prepared and characterized by Fourier transform infrared spectra, X-ray powder diffraction, (1)H NMR, electrospray ionization mass spectrometry, and thermogravimetric analyses. Results showed that the host-guest stoichiometries in the inclusion complexes were all 1:1 both in solid state and in aqueous solution. As for the same host, the values of K increased in the order EOB < BOB < DOB, in strong association with the fan handle in the fanlike molecules; that is to say, the K values increased with increasing carbon chain length of substituent on benzene ring. In addition, the K values of DOMB complexes were larger than those of DOB complexes for the same CD, indicating that the introduction of an extra o-methoxyl group on DOB further stabilized the CD inclusion complexes. The decomposition activation energies of EOB-beta-CD and DOB-beta-CD were very similar but significantly larger than that of free beta-CD.

Effects of paclitaxel on proliferation and apoptosis in human acute myeloid leukemia HL-60 cells.

AIM: To investigate the regulatory effect of paclitaxel on proliferation and apoptosis in human acute leukemia HL-60 cells. METHODS: HL-60 cell growth was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tertrazolium bromide (MTT) colorimetric assay. Cell cycle kinetics and apoptosis were analyzed by flow cytometry and microscopic examination. In addition, DNA microarrays containing 14,400 EST elements were used to investigate the gene expression pattern of HL-60 cells exposed to paclitaxel 1 micromol/L. RESULTS: Paclitaxel inhibited HL-60 cell growth significantly in a dose-dependent and time-dependent manner (P<0.01). Marked cell accumulation in G2/M phase and multinucleated cells were also observed after treatment with paclitaxel 0.1 and 1 micromol/L. Among 14400 EST elements, 277 genes were found to be markedly up- or down-expressed in the HL-60 cells treated with paclitaxel 1 micromol/L for 0.5 h, comprising 210 known genes and 67 unknown genes. CONCLUSION: Paclitaxel suppresses the growth of HL-60 cells in vitro by causing cell-cycle arrest and apoptosis. The results of microarray suggest that paclitaxel initiates apoptosis through multiple mechanisms.