-Skin-lung-liver-kidney-and-heart-DNA-preparations-were-assayed-by-nuclease-P1enhanced-postlabeling-l

Adduct View more were tissue-specific and displayed a multitude of non-polar DNA adducts with levels amounting to one adduct in 1 x chromatographic properties, these adducts appeared largely derived from polycyclic aromatic hydrocarbons (PAHs) present in the extracts. One of the major adducts was identified as the 32P-labeled derivative of the reaction product of 7 beta, 8 alpha-dihydroxy-9 alpha, 10 alpha-epoxy-7, 8,9,10-tetrahydrobenzo[a]pyrene (BPDE I) with N2 of deoxyguanosine. Total non-polar DNA adduct levels were highest in skin and lung, amounting to 17 and 24% of the skin values for extracts 1 and 2, respectively, in lung while the corresponding levels in liver were 5 and 12%. These results were in accord with the carcinogenic potencies of PAHs in these organs. Extract 2 induced higher adduct levels in internal organs, although its PAH concentrations were lower than those of extract 1, i.e.

6-butyl-n-hydroxynaphthimide trifluoromethanesulfonic acid as a Catalyst in Organic Transformations , liver, kidney, and heart had 1, 2, 1, and 1 times higher total adduct levels and 1, 3, 1, and 1 times higher benzo[a]pyrene adduct levels. With the exception of total adducts in lung, the differences between the two extracts were all significant, suggestive of compound interactions. Photo Acid Generator [a]pyrene adduct levels in the five tissues correlated linearly with total adduct levels and thus represented a surrogate for the latter. Overall, the results suggest that DNA adducts in mouse tissues, as analyzed by 32P-postlabeling, are suitable biomarkers and dosimeters of the Protomer-Specific Photochemistry Investigated Using Ion Mobility Mass The utility of tandem ion mobility mass spectrometry coupled with electronic spectroscopy to investigate protomer-specific photochemistry is demonstrated by measuring the photoisomerization response for protomers of protonated 4-dicyanomethylene-2-methyl-6-para-dimethylaminostyryl-4H-pyran (DCM) molecules. The target DCMH+ species has three protomers that are distinguished by their different collision cross sections with He, N2, and CO2 buffer gases, trends in abundance with ion source conditions, and from their photoisomerization responses. The trans-DCMH+ protomers with the proton located either on the tertiary amine N atom or on a cyano group N atom exhibit distinct S1← S0 photoisomerization responses, with the maxima in their photoisomerization action spectra occurring at 420 and 625 nm, respectively, consistent with predictions from accompanying electronic structure calculations. The cis-DCMH+ protomers are not distinguishable from one another through ion mobility separation and give no discernible photoisomerization or photodissociation response, suggesting the dominance of other deactivation pathways such as fluorescence.

The study demonstrates that isobaric protomers and isomers generated by an electrospray ion source can possess quite different photochemical behaviors and emphasizes the utility of isomer and protomer selective techniques for exploring the spectroscopic and photochemical properties of protonated molecules in the gas Toward a photochemical and thermal molecular machine: reversible ligand dissociation and binding in a ruthenium(II)-2,2'-bipyridine complex with A Ru(II) complex having tris(2-pyridylmethl)amine (TPA) and 2,2'-bipyridine the coordination of the axial pyridine moiety of TPA due to steric hindrance. The complex showed interesting dissociation-binding behavior of the axial pyridine arm to form a solvent adduct with TPA ligation in a unique meridional tridentate fashion. The complex undergoes thermal dissociation to form solvent-coordinated species via an S(N)2-like mechanism with activation energy of 117 kJ/mol. In contrast, the complex showed reversible photochemical dissociation and rebinding via an S(N)1-like mechanism by MLCT irradiation. The photochemical dissociation was accelerated approximately 200-fold faster than the thermal process. The dissociation process involves selective binding behavior toward external ligands (solvents) with pi-acceptor character, which is indispensable, and no sigma-donating molecules could bind to the Ru(II) center. The guest molecule can be released upon photoirradiation after its thermal Surface Wettability Tuning of Acrylic Resin Photoresist and Its Aging Education, School of Materials Science and Engineering, Sun Yat-sen University, Photoresist is the key material in the fabrication of micropatterns or microstructures.

Tuning the surface wettability of photoresist film is a critical consideration in its application of microfluidics. In this work, the surface wettability tuning of acrylic resin photoresist by oxygen plasma or ultra-violet/ozone, and its aging performance in different atmospheres, were systematically studied. The chemical and physical characterizations of the surfaces before and after modification show a dramatic decrease in the C-C group and increase in surface roughness for oxygen plasma treatment, while a decrease of the C-C group was found for the UV/ozone treatment. The above difference in the surface tuning mechanism may explain the stronger hydrophilic modification effect of oxygen plasma.