DNA Damage in Rheumatoid Arthritis: An Age-Dependent Increase in the Lipid Peroxidation-Derived DNA Adduct, Heptanone-Etheno-2′-Deoxycytidine

Objective. To evaluate what types of DNA damages are detected in rheumatoid arthritis (RA). Methods. The DNA adducts such as 8-oxo-hydroxy-7,8-dihydro-2′-deoxyguanosine (8-oxo-dG), 1,N6-etheno-2′-deoxyadenosine (εdA), and heptanone-etheno-2′-deoxycytidine (HεdC) in genomic DNAs, derived from whole blood cells from 46 RA patients and 31 healthy controls, were analyzed by high-performance liquid chromatography tandem mass spectrometry, and their levels in RA patients and controls were compared. In addition, correlation between DNA adducts and clinical parameters of RA was analyzed. Results. Compared with controls, the levels of HεdC in RA were significantly higher (P<0.0001) and age dependent (r = 0.43, P < 0.01), while there was no significant difference in 8-oxo-dG and εdA accumulation between RA patients and controls. HεdC levels correlated well with the number of swollen joints (r = 0.57, P < 0.0001) and weakly with the number of tender joints (r = 0.26, P = 0.08) of RA patients, while they did not show a significant association with serological markers such as C-reactive protein and matrix metalloproteinase 3. Conclusion. These findings indicate that HεdC may have some influence on the development of RA and/or its complications

Photoresponsive Behaviors of Azobenzene Functionalized 2-Arm, 3-Arm, and 4-Arm Telomers: A Comparative Study

Azobenzene functionalized 2-arm, 3-arm, and 4-arm telomers were synthesized according to the synthetic process described earlier. Here we report their photoresponsive behaviors to elucidate the effects of number of arms of star azotelomers on their photoresponsive behaviors. Photoisomerization behaviors of star azotelomer films were investigated. Surface relief gratings were inscribed on spin-coated azotelomer films by irradiating interference pattern of Ar+ laser at 488 nm. Diffraction efficiencies of azotelomers were found to increase with an increase in number of arms. The formation of surface relief gratings (SRG) was observed with atomic force microscopy (AFM) and optical polarized microscopy

Thermal and Photo Alignment Behavior of Polyethylene Imine Having Methoxy Substituent Azobenzene Side Chain Group

Novel type of polyethylene imine having methoxy (–OCH3) substituent azobenzene side chain group through eight methylene spacer group (PEI8M) was successfully synthesized and characterized by the polymer by 1H NMR, differential scanning calorimetry, polarized optical microscopic and X-ray diffraction analysis. Synthesized polymer possessed liquid crystalline (LC) properties. Spin coated PEI8M film showed out-of-plane molecular orientation on annealing and non-polarized visible light irradiation. PEI8M in solid film exhibited photoresponsive properties upon irradiation of UV and visible light. PEI8M film also exhibited reversible molecular orientation from random state to out-of-plane and from out-of-plane to random state on annealing, non-polarized UV and visible light irradiation

Photo-induced orientation behaviors of azobenzene liquid crystal copolymers for photonic crystals

A certain wavelength of incident light is forbidden based on the optical periodicity related to the intervals and refractive indices of the comprising materials. For multi-bilayered films with periodicity, on–off switching of reflection is possible due to the presence or absence of a refractive index difference between two consisting films. Changes in the refractive index can be induced by stimuli-responsive orientation behaviors of liquid crystal (LC) molecules with birefringence. Azobenzene (Az) groups are employed for photo response and copolymerized with non-photo-responsive LC mesogen groups for cooperative orientation to improve light penetration by the dilution of Az concentration. LC mesogen groups are designed to have a high refractive index to improve the reflection contrast. The refractive indices and the orientation behaviors of the copolymer films are investigated. On–off switching of reflection for multi-bilayered films consisting of alternate Az-containing LC copolymers and poly vinyl alcohol is conducted using ultraviolet and visible light irradiation, and their reflection intensity and response speed are compared between the different LC mesogen types and molar ratios

On-off switching properties of one-dimensional photonic crystals consisting of azo-functionalized polymer liquid crystals having different methylene spacers and polyvinyl alcohol

In this paper, photoresponsive behavior of multi-bilayered films having precisely controlled layer thickness prepared by stacking an azo-functionalized polymer liquid crystal, PMAzXAc, and polyvinyl alcohol alternatively, PVA, is described. The multi-bilayered films were found to reflect a light of specific wavelength depending on the layer thickness and refractive index, and showed the reversible change in the reflection intensity by irradiation with visible and UV lights. The change in the reflection intensity was brought about by change in the molecular orientation of PMAzXAc between an out-of-plane orientation and a photo-induced isotropic state, and was strongly dependent on the number of methylene spacer of PMAzXAc linking the azobenzene side group with the acrylate polymer main chain. PMAz6Ac with hexa-methylene spacer showed the largest change in the reflection intensity, while smaller change in the reflection intensity was observed for PMAzXAc having shorter or longer methylene spacer than 6. The effect of the methylene spacers on the photochemical change in the molecular orientation of azobenzene chromophores in the multi-bilayered films will be discussed

Adsorption and release on three-dimensional graphene oxide network structures

In this study, three-dimensional network architectures are constructed using nano-sized graphene oxide (nGO) as the building block. The cross-linking reaction of nGO is conducted in sub-micrometre water droplets in an emulsion system to control the size of the networks by restricting the reaction space. Two types of three-dimensional GO networks with different cross-linking lengths were constructed, and their methyl orange adsorption and release behaviours were investigated under external stimuli, such as thermal treatment, ultrasonic wave treatment and near-infrared light irradiation

Manipulation and assembly of small objects in liquid crystals by dynamical disorganizing effect of push-pull-azobenzene-dye

The phase transition of a nematic liquid crystal containing a push-pull azobenzene dye could be induced efficiently during irradiation with visible light. The dynamical disorganizing effect of the push-pull azobenzene dye on the liquid crystalline order through its trans-cis-trans photoisomerizaion cycle under visible light was contributed to the efficient phase transition. Then, the effects of light irradiation on the motion of small objects dispersed in the liquid crystals containing the push-pull azobenzene were explored and the manipulation and assembly of those objects were successfully achieved in the nematic phase but also in the smectic phase. The combination of the photo-controlled dynamical change in the liquid crystalline order and the intrinsic self-assembly property of a liquid crystal is promising for use in technologies that require not only the organization of small objects but also the photo-driving of nano- and micro-sized mechanical materials