Micelles-template induced organic nanocrystals based on iodo…nitro interactions

The nanocrystals based on a polar organic compound INBP （4-iodo-4＇-nitrobiphenyl） have been fabricated by reprecipitation approach. For the formation of INBP based nanocrystals, the intermolecular iodo…nitro interaction is the dominant driving force and the micelles formed by the surfactant CTAB （cetyltrimethylammonium bromide） molecules are the efficient templates for controlling morphologies of nanocrystals. The field emission scanning electro microscope （FESEM） images demonstrated that prism-like and needle-like nanocrystals of INBP were formed in pure water and micell containing aqueous solution, respectively. XRD pattern and UV/vis absorption spectra were employed to characterize the nanocrystals.     

Study on peptide-peptide interaction using high-performance affinity chromatography and quartz crystal microbalance biosensor

The specific interaction between sense and antisense peptides was studied by high-performance affinity chromatography （HPAC） and quartz crystal microbalance （QCM） biosensor. Fragment 1-14 of human interferon-β （hlFN-βwas chosen as sense peptide and its three antisense peptides （AS-IFN 1, AS-IFN 2, and AS-IFN 3） were designed according to the degeneracy of genetic codes. The affinity column was prepared with sense peptide as ligand and the affinity chromatographic behavior was evaluated. Glu-substituted antisense peptide （AS-IFN 3） showed the strongest binding to immobilized sense peptide at pH 7.5. A quartz crystal microbalance-flow injection analysis （QCM-FIA） system was introduced to investigate the recognition process in real-time. The equilibrium dissociation constants between sense peptide and AS-IFN 1, AS-IFN 2 and AS-IFN 3 measured 2.08×10^-4, 1.31×10^-4 and 2.22×10^-5 mol/L, respectively. The mechanism study indicated that the specific recognition between sense peptide and AS-IFN 3 was due to sequence-dependent and multi-modal affinity interaction.     

Concentration level and distribution of polycyclic aromatic hydrocarbons in soil and grass around Mt. Qomolangma, China

High mountains may serve as a condenser for persistent organic pollutants. In the present study, soil and grass samples from Mt. Qomolangma region, China were collected from 4600 to 5620 m a.s.I and were analyzed for polycyclic aromatic hydrocarbons （PAHs） to determine if they are concentrated at colder, more elevated sites and to evaluate their possible resources and fractionation. The total PAHs concentration in soil samples was 〈 600 ng g^-1, the critical value to differentiate PAHs levels in remote and urban regions. This implied the PAHs levels at Mt. Qomolangma are relatively low and what one might expect in such a remote region of the world. These low values may represent a soil background for mid-latitude Northern Hemisphere soils away from the direct influence of an anthropogenic source. As for the distribution pattern, the low molecular weight PAHs were prone to accumulate at higher altitude, while the high molecular weight PAHs inversely related or unrelated with elevation. Based on high concentration of phenanthrene at elevated sample site and the ratios of individual PAHs, we deduced that home-heating combustion and vehicle emission may result in the constitution trait of PAHs in this mountain region. Monsoon traveling over India, Pakistan and other countries with dense population may carry contaminant to Mt. Qomolangma region.     

Coherent thermal radiation in thin films and its application in the emissivity design of multilayer films

The infrared transmission spectra of a 0.54-μm-thick Ge film and a 20-μm-thick Si film were experimentally measured. As the incident radiation was in the wavelength range from 1.5μm to 10μm, the Ge film demonstrated a strongly spectral coherence. However, thermal radiation of the Ge film was found to be spatially incoherent due to its extreme thinness. The Si film exhibited significantly spectral and spatial coherence. The results confirmed that thermal radiation of a monolayer film could be coherent spectrally and spatially if the film thickness was comparable with the wavelength. The optical characteristic matrix method was applied to calculate the transmission spectra of the Si and Ge film, and the results agreed well with the measurements. This method was further used to analyze two multilayer films composed of five low emissive layers. Their emissivities were found to be highly emissive at a certain zenith angle, and the emissive peak could be controlled by careful selection of film thickness.     

Investigation of adsorption of surfactant at the air-water interface with quantum chemistry method

Density functional theory （DFT） of quantum chemistry was used to optimize the configuration of the anionic surfactant complexes CH3（CH2）7OSO3^- （H2O）n （n=0-6） and calculate their molecular frequencies at the B3LYP/6-311＋G^＊ level. The interaction of CH3（CH2）7OSO3^- with 1 to 6 water molecules was investigated at the air-water interface with DFT. The results revealed that the hydration shell was formed in the form of H-bond between the hydrophilic group of CH3（CH2）7OSO3^- and 6 waters. The strength of H-bonds belongs to medium. Binding free energy revealed that the hydration shell was stable. The increase of the number of water molecules will cause increases of the total charge of hydrophilic group and S10-O9-C8 bond angle, but decreases of the alkyl chain length and the bond lengths of S10-O11, S10-O12 as well as S10-O13, respectively.     

The c-myc coding DNA sequences of cyprinids （Teleostei： Cypriniformes）： Implications for phylogeny

The family Cyprinidae is one of the largest fish families in the world, which is widely distributed in East Asian, with obvious difference in characteristic size among species. The phylogeneUc analysis of cyprinid taxa based on the functionally important genes can help to understand the speciation and functional divergence of the Cyprinidae. The c-myc gene is an important gene regulating individual growth. In the present study, the sequence variations of the cyprinid c-myc gene and their phylogenetic significance were analyzed. The 41 complete sequences of the c-myc gene were obtained from cyprinids and outgroups through PCR amplification and clone. The coding DNA sequences of the c-myc gene were used to infer molecular phylogenetic relationships within the Cyprinidae. Myxocyprinus asiaticus （Catostomidae）, Misgurnus anguillicaudatus （CobiUdae） and Hemimyzon sinensis （Homalopteridae） were assigned to the outgroup taxa. Phylogenetic analyses using maximum parsimony （MP）, maximum likelihood （ML）, and Bayesian retrieved similar topology. Within the Cyprinidae, Leuciscini and Barbini formed the monophyletic lineage respectively with high nodal supports. Leuciscini comprises Xenocyprinae, CuItrinae, East Asian species of Leuciscinae and Danioninae, Gobioninae and Acheilognathinae, and Barbini contains Schizothoracinae, Barbinae, Cyprininae and Labeoninae. Danio rerio, D. myersi and Rasbora trilineata were supposed to separate from Leuciscinae and Barbini and to form another lineage. The positions of some Danioninae species were still unresolved. Analyses of both amino acid variation with parsimony information and two high variation regions indicated that there is no correlation between variations of single amino acid or high variation regions and characteristic size of cyprinids. In addition, the species with smaller size were usually found to be basal within clades in the tree, which might be the results of the adaptation to the primitive ecology and survival pressure.     

Experimental investigation of incremental reactivity of di-tert-butyl peroxide

Large quantities of di-tert-butyl peroxide (DTBP) have been emitted into the troposphere due to human activities. Its role in the atmospheric photochemical reaction has not been understood. This study presents the results of the photochemical reactions of DTBP and NOx, which have been simulated in a self-made smog chamber under the temperature of (29±1)℃. Both the wall decays of ozone and NO2 could be neglected, compared to the results in simulative experiments. The effective intensity of UV light used in the experiments was 1.28×10-3 s-1, which was expressed by the rate constant of NO2 photolysis in purified air. The reaction mechanism was proposed according to our results and reports of other researchers. The maximum values of incremental reactivity (IR) in the three simulative ex- periments were 9.53×10-2, 5.23×10-2 and 3.78×10-2, respectively. The incremental reactivity decreased with the increase of initial concentrations of DTBP. The IR value of DTBP obtained in this study was comparable to that of acetylene reported in our previous research.     

Reconstruction of linkage maps in the distorted segregation populations of backcross, doubled haploid and recombinant inbred lines

Non-Mendelian segregation of markers, known as distorted segregation, is a common biological phenomenon. Although segregation distortion affects the estimation of map distances and the results of quantitative trait loci (QTL) mapping, the effects of distorted markers are often ignored in the construction of linkage maps and in QTL mapping. Recently, we have developed a multipoint method via a Hidden Markov chain method to reconstruct linkage maps in an F2 population that corrects for bias of map distances between distorted markers. In this article, the method is extended to cover backcross, doubled haploid and recombinant inbred line (RIL) populations. The results from simulated experiments show that: (1) the degree that two linked segregation distortion loci (SDL) affect the estimation of map distances increases as SDL heritability and interval length between adjacent markers increase, whereas sample size has little effect on the bias; (2) two linked SDL result in the underesti- mation of linkage distances for most cases, overestimation for an additive model with opposite additive effects, and unbiased estimation for an epistatic model with negative additive-by-additive effects; (3) the proposed method can obtain the unbiased estimation of linkage distance. This new method was applied to a rice RIL population with severely distorted segregation to reconstruct the linkage maps, and a bootstrap method was used to obtain 95% confidence intervals of map distances. The results from real data analysis further demonstrate the utility of our method, which provides a foundation for the inheritance analysis of quantitative and viability traits.