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Epigenetic mutations caused by pollutants are possibly linked to many diseases. Benzo(a)pyrene (BaP) is one of the most representative air pollutants and has aroused wide concern because of its strong carcinogenicity. The reproductive toxicity induced by BaP has been identified, but little is known about the characteristics of the methylation changes induced by BaP. In this study, a methylated DNA immunoprecipitation sequencing method was used to detect the methylation of sperm DNA of rats exposed to BaP. Compared with the respective genes in normal rats, there were 3227 hypomethylated genes and 828 hypermethylated genes after BaP exposure. Gene ontology enrichment analysis reported that differentially methylated genes (DMGs) were enriched in the localization, single-multicellular organism process and plasma membrane. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the DMGs were significantly enriched in the Ras signalling pathway, Rap1 signalling pathway, pancreatic secretion and neuroactive ligand–receptor interaction. DisGeNET disease spectrum analysis showed that DMGs were associated with infertility and certain genetic diseases. Further research needs to be done to explore whether these abnormal methylation are transgenerational.

In recent years, Phalaenopsis has become a very popular potted flower for the international flower market. The aim of this work was to build a tissue-specific transcriptome to obtain genomic data about the biosynthesis of anthocyanins in Phalaenopsis, compare gene expression levels in different colored Phalaenopsis plants, and to ultimately analyze the anthocyanin biosynthetic pathway in Phalaenopsis. Illumina sequencing technology obtained 888749 and 1057077 sequencing contigs in red and yellow Phalaenopsis buds, respectively. De novo assemblies yielded 51771 unigenes, and 801 differentially expressed genes were obtained using the reads. These included 358 up-regulated and 443 down-regulated genes in the yellow bud compared with the red bud. Many of the identified differentially expressed genes were related to the biosynthesis of anthocyanins. Quantitative real-time PCR confirmed expression levels of key genes and transcription factors involved in anthocyanin biosynthesis in Phalaenopsis were the same as in our dataset. Our findings allowed the deduction of the anthocyanin biosynthetic pathway in Phalaenopsis.

Electroless plating of copper on poly(tetrafluoroethylene) (PTFE) films modified by NH3 plasma treatment and surface graft copolymerization with aniline had been carried out. For the electroless plating of copper, the polyaniline (PANI)-grafted PTFE (PANI-g-PTFE) surface, with the PANI in its fully reduced leucoemeraldine form, was activated directly in the Pd(NO3)2 acid solution in the absence of prior sensitization by SnCl2. The compositions and chemical states of the PTFE surfaces during each stage of the surface modification, surface activation, and electroless deposition processes were studied by x-ray photoelectron spectroscopy (XPS). The adhesion strength of the electroless deposited copper on the PANI-g-PTFE surface exhibited a strong dependence on the graft concentration of PANI. A T-peel adhesion strength of about 5 N/cm was achieved for the electrolessly deposited Cu on the PANI-g-PTFE surface (the Cu/PANI-g-PTFE assembly). The high adhesion strength of the Cu/PANI-g-PTFE assembly was attributed to the synergistic effects of strong interactions between the grafted aniline polymer and the metal (including Pd) atoms, the spatial distribution of the PANI chains in the metal matrix, and the fact that the polyaniline chains were covalently tethered on the PTFE surface. XPS results also revealed that the Cu/PANI-g-PTFE assemblies delaminated by cohesive failure inside the PTFE film.

The effect of γ-ray irradation on the emeraldine (EM) base form of polyaniline was investigated. The process of γ-ray, UV, and thermally-induced graft copolymerization of EM base with acrylic acid (AAc) in a number of solvents and co-solvents were compared in an attempt to prepare a water-solube EM through N-acylation. The presence of N-acylation was investigated by thermogravimetric (TG) analysis, Fourrier transform infrared (FTIR) spectroscopy., and X-ray photoelectron spectroscopy (XPS). In all cases, the grapht concentration and the resulting surface conductivity were shown to be a function of the monomer concentration. The thermostability and weight loss behavior of the grapht-copolymerized EM included those that were characteristic of the EM base, the AAc polymer and the amide polymer. Some of the grapht-modified EM base samples exhibited good water solubility. In particular, the γ-ray-induced graft copolimerization of EM with AAc in N-methyl-2-pyrrolodinone (NMP)/water co-solvent readily gave rise to a water soluble, self-protonated and semi-conductive EM, which could be cast into free-standing films from an aqueous solution.

High-resolution X-ray photoelectron spectroscopic (XPS) measurements of the various intrinsic redox states of polyaniline (PANI), using a monochromatized Al—Kα source, were carried out. The presence of the imine, amine and positively charged nitrogen species corresponding to a particular intrinsic redox state and protonation level of the polymer was resolved quantitatively and unambiguously. The result confirmed the peak assignments of former XPS core-level studies using the lower resolution non-monochromatized Mg—Kα X-ray source. Thus, the high-resolution XPS using a monochromatized Al—Kα X-ray source is a truly unique tool for the convenient and quantitative analysis of the various intrinsic redox states of PANI.

This work focused on the studies of the high-temperature dependence of the responsivity of ZnS, ZnSTe and ZnSSe photodiodes. It was found that in general the responsivity at higher temperatures will shift to longer wavelengths because of band gap narrowing. A remarkable observation is that the near-band-edge responsivities of these diodes increase at higher temperature. We believe that this observation is attributed to the change of the density of state distribution due to lattice expansion at high temperature and a simplified model is used to illustrate this hypothesis.

Angle-resolved X-ray photoelectron spectroscopy was employed for the in situ study of the interactions between thermally evaporated copper atoms and conjugated electroluminescent polymer, such as poly(p-phenylene vinylene) and its soluble derivative, poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV). Quantitative changes in the C 1s and Cu 2p core-level spectra, the Cu LMM Auger line shapes, and the chemical stoichiometries of polymer–metal interfaces with progressive deposition of the copper atoms were carefully monitored. Chemical interactions had occurred between each polymer and the copper atoms, resulting in the formation of an interfacial layer of metal complexes. There appeared to be no significant migration of bulk absorbed oxygen to the polymer surface upon copper deposition unlike that observed during the deposition of metals of lower work function. Diffusion of Cu atoms into the near-surface region of the polymer was observed for PPV and MEH-PPV films. The interactions of the Cu atoms with the polymer surfaces were also compared with the results obtained for the Al/PPV and Al/MEH-PPV interfaces.

X-ray photoelectron spectroscopy was employed for an in situ study of the interactions between thermally evaporated magnesium atoms and polyaniline films of various intrinsic oxidation states. Quantitative changes in the N 1s core-level spectra, the Mg 2p core-level spectra and the surface chemical stoichiometries of these films throughout the magnesium evaporation process were carefully monitored. Although the nitrogen sites appeared to be more attractive to the incoming magnesium atoms, and the emeraldine and nigraniline films underwent an apparent decrease in the intrinsic oxidation state ([N]/[NH] ratio) as a result of magnesium evaporation, there is no direct interaction between the two species. On the other hand, the adsorbed oxygen from the bulk of the polymer film played a dominant role in the interfacial interactions between the polymer and the metal.

X-ray photoelectron spectroscopy (XPS) was employed for the study of the physicochemical interactions at electrode/polymer interfaces involving metals of high and low work functions and thin films of poly(p-phenylene vinylene) (PPV) and poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV). The changes in the C 1s core-level line shape of the polymers, the evolution of the metal core-level spectra and the changes in chemical compositions at the interfaces involving polymer coated on indium-tin oxide (ITO), sputtered ITO on polymer, and in situ evaporated magnesium (Mg) on polymer were carefully monitored. Indium of the ITO in both the ITO/polymer and polymer/ITO assemblies was found to diffuse towards the polymer at the interface. Oxygen migration was also observed at the ITO/polymer interfaces. The results obtained from in situ analysis by angle-resolved XPS of the interactions between thermally evaporated Mg and PPV and Mg and MEH-PPV indicated the formation of an interfacial layer in each case. The surface diffusion of adsorbed oxygen from the bulk of the conjugated polymer film played a dominant role in the interfacial reactions. The interfacial layer consisted of Mg oxides, Mg clusters, Mg metal and Mg-polymer complexes.

Simultaneous lamination of emeraldine base (EB) films of polyaniline (PANI) was achieved during thermally induced surface graft copolymerization with various monomers, such as N,N′-dimethyl(methacryloylethyl)ammonium propanesulfonate (DMAPS), sodium salt of styrenesulfonic acid (NaSS), 1-vinyl imidazole (VIDz) and acrylic acid (AAc). The simultaneous thermal grafting and lamination process can be carried out under atmospheric conditions, and in the complete absence of an added polymerization initiator and surface preactivation of the EB substrates. The structure and chemical composition of the graft copolymerized surfaces from the self-delaminated junction in water were investigated by X-ray photoelectron spectroscopy (XPS). The effects of monomer concentration, thermal grafting/lamination temperature, and the physicochemical attributes of the various monomers on the observed lamination strength were studied. The efficiency of surface graft copolymerization and the lamination strength were found to increase with increasing temperature in the temperature range of 80–120°C. Maximum lap shear adhesion strengths of greater than 350 N/cm2 and exceeding the yield strength of the substrate EB film could be readily achieved for grafting/lamination carried out in the presence of DMAPS, VIDz and AAc monomer.

Adhesion of emeraldine base (EB) films of polyaniline (PANI) to plasma-pretreated polytetrafluoroethylene (PTFE) films and to copper foils were achieved via thermally induced surface graft copolymerization with concurrent lamination. The process was carried out under atmospheric conditions in the presence of pure and aqueous solutions of 1-vinyl imidazole (VIDz) or acrylic acid (AAc) and in the absence of an added polymerization initiator. The chemical composition and microstructure of the graft copolymerized surfaces from the self-delaminated junction in water and from the mechanically delaminated interfaces were investigated by X-ray photoelectron spectroscopy (XPS). The effects of monomer concentration and thermal grafting/lamination temperature on the observed lamination strength were studied for both the EB/PTFE and EB/Cu interfaces. The lap shear adhesion strength of the EB/PTFE junction also depended on the plasma pretreatment time of the PTFE surface. Maximum lap shear adhesion strength approaching 200 N/cm2 was obtained for the EB/PTFE interface laminated at 140°C for 1 h in the presence of pure AAc monomer and with 40 s of Ar plasma pretreatment time for the PTFE surface. A maximum lap shear adhesion strength of about 640 N/cm2 could be readily achieved for the EB/Cu interface for grafting/lamination carried out in the presence of 25 vol% aqueous VIDz solution at 130°C.

The surface microhardness of conventional thermoplastics lie between 0.1 and 0.6 GPa. The as-cast emeraldine (EM-25) base film of polyaniline (PANi) exhibits a surface microhardness of about 1 GPa. The hardness is increased to about 4 GPa in the highly cross-linked EM (EM-150) film. This hardness value is further enhanced to about 6 GPa after 1 cycle of acid−base treatment. The hardness of the EM-150 film can also be enhanced to about 8 GPa through protonation or through reduction to the leucoemeraldine state. Surface modification of the EM-150 films via graft copolymerization with acrylic acid or styrenesulfonic acid readily gives rise to hard-surfaced PANi films having microhardness values approaching 20 GPa. This surface hardness is comparable to many of those reported for the very hard-surfaced conventional polymers from high-energy ion-beam bombardments. The surface hardness of the surface-modified EM-150 film arises from the additional covalent bonding of the graft chains on the highly cross-linked ...

The results obtained from the in situ analysis by angle resolved x-ray photoelectron spectroscopy (XPS) of the interactions between thermally evaporated metals (aluminum and indium) and conjugated electroluminescent polymer films, such as poly(p-phenylene vinylene) and its soluble derivative, poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV), are reported. The changes in the carbon and metal core-level spectra and the chemical stoichiometries of polymer–metal interfaces with progressive deposition of the metal atoms were monitored. The interactions of the Al and In atoms with the polymer surfaces were compared. For both metals, a simple electrical contact was not formed. From the XPS studies, it was deduced that chemical reactions had occurred between the polymer and the metal, leading to the formation of an interfacial layer of metal oxides and complexes. The interfacial reactions were promoted by the surface oxidation states of the polymer, the migration of bulk adsorbed oxygen to t...

Surface modification of electroactive polyaniline (PANi) films by gas plasma treatment, corona discharge treatment, vacuum ultra-violet (VUV) exposure, and surface graft copolymerization has been carried out. Exposure of the nigraniline-like films of PANi to argon plasma, oxygen plasma, corona discharge and VUV, followed by atmospheric exposure, resulted in the oxidation of the carbon atoms to various extents. Carbon oxidation, in turn, caused a decrease in the intrinsic oxidation state ([N/[NH] ratio) of the aniline polymer. The as-cast and noncrosslinked emeraldine (EM-25) film of PANi exhibited a surface micro-hardness of about 1 GPa. The hardness was further enhanced to about 6 GPa in the highly crosslinked EM (EM-150) film after one cycle of acid–base treatment. Surface modification of the crosslinked EM film via surface graft copolymerization with acrylic acid or styrenesulfonic acid could give rise to semi-conductive and super-hard-surfaced PANi films having micro-hardness values approaching 20 GPa. This surface hardness is comparable to those reported for the super-hard-surfaced conventional polymers from high-energy ion-beam bombardment. Copyright © 1999 John Wiley & Sons, Ltd.