The immunosuppressive effects of phthalocyanine photodynamic therapy in mice are mediated by CD4+ and CD8+ T cells and can be adoptively transferred to naive recipients

Photodynamic therapy (PDT) is a promising treatment modality for malignant tumors but it is also immunosuppressive which may reduce its therapeutic efficacy. The purpose of our study was to elucidate the role of CD4+ and CD8+ T cells in PDT immunosuppression. Using silicon phthalocyanine 4 (Pc4) as photosensitizer, nontumor-bearing CD4 knockout (CD4-/-) mice and their wild type (WT) counterparts were subjected to Pc4-PDT in a manner identical to that used for tumor regression (1 cm spot size, 0.5 mg kg(-1) Pc4, 110 J cm(-2) light) to assess the effect of Pc4-PDT on cell-mediated immunity. There was a decrease in immunosuppression in CD4-/- mice compared with WT mice. We next examined the role of CD8+ T cells in Pc4-PDT-induced immunosuppression using CD8-/- mice following the same treatment regimen used for CD4-/- mice. Similar to CD4-/- mice, CD8-/- mice exhibited less immunosuppression than WT mice. Pc4-PDT-induced immunosuppression could be adoptively transferred with spleen cells from Pc4-PDT treated donor mice to syngenic naive recipients (P < 0.05) and was mediated primarily by T cells, although macrophages were also found to play a role. Procedures that limit PDT-induced immunosuppression but do not affect PDT-induced regression of tumors may prove superior to PDT alone in promoting long-term antitumor responses.     

Multi Fuzzy Fractal Theorems in Fuzzy Metric Spaces

The Hutchinson-Barnsley (HB) operators are studied for multi iterated function system in a general setting. Some existence and uniqueness results are obtained in fuzzy fractal and multi fuzzy fractal spaces. From them, we obtain our results, which generalize some recent results in the literature.     

Raman spectroscopic studies of pulsed laser‐induced defect evolution in graphene

Raman spectra were obtained for graphene after irradiating the samples by pulsed laser (λ = 248 nm). Changes in the spectra were observed as the pulse laser energy density (PLED) was varied from 0.1 to 0.25 J/cm². Changes in bilayer graphene were accompanied by the appearance of the D peak and the broadening of the G peak. Changes in multilayer graphene are more profound as the Raman spectra changes from a multilayer to bilayer and subsequently to monolayer graphene in response to a slow increase in the PLED. The threshold PLED was found to be dependent on the number of graphene layers. We also irradiate graphene with very high PLED (much above the threshold), and the Raman spectra were found to be significantly changed. The G‐band became broader, and red shifted, while the intensity of the 2D‐band was drastically reduced and an intense defect‐related D peak appeared at about 1350 cm⁻¹. The laser ablation of graphene, both with low‐ and high‐energy intensity, is consistent with the reported theoretical predictions. Copyright © 2013 John Wiley & Sons, Ltd.     

A comparative study of the BaTiO3 film and the BaTiO3/(Ba0.7Sr0.3)TiO3 superlattice using X-ray diffraction and raman spectroscopy

A comparative study of the BaTiO₃ epitaxial film and the BaTiO₃/(Ba_0.7Sr_0.3)TiO₃ superlattice prepared by pulsed laser deposition on MgO(100) substrates has been performed. The complete parallel orientation of the film and the substrate has been established and the modulation period of the superlattice ?? = 28 nm, the parameters of the unit cell averaged over the period of the superlattice ??, and the unit cell parameters of the layers forming the superlattice have been determined using the X-ray diffractometry data. According to the X-ray diffraction data, the unit cell of the BaTiO₃ single-component film and the unit cell averaged over the period of the superlattice ?? are pseudocubic; however, an analysis of the polarization characteristics of the Raman spectra has suggested that the film and the superlattice have monoclinic symmetry (P _x = P _y ?? 0, P _z ?? 0). The transformation of the components of the soft mode due to the deformation of the epitaxial layers forming the superlattice has been discussed.     

Divide line between relaxor,diffused ferroelectric,ferroelectric and dielectric

The dielectric spectroscopic studies of relaxor ferroelectric Ba(Ti_0.70Sn_0.30)O₃ (BTS30), diffused ferroelectric Ba(Ti_0.70Sn_0.20)O₃ (BTS20), classical ferroelectric BaTiO₃ (BT0), and normal dielectric Ba(Fe_0.50Ta_0.50O₃) (BFT) were carried out in the temperatures ～100 K–650 K, and frequencies ～100 Hz–1 MHz, which showed relaxor behavior at 130 K with typical 30 K frequency dispersion, perfect diffused ferroelectric character at 190 K, classical ferroelectric, and dielectric relaxation at 450 K–550 K respectively. A divide line was sketched between the relaxors, ferroelectrics and normal dielectrics based on the Maxwell–Wagner space charge model. The impedance spectroscopy and ac conductivity spectroscopy were carried out to explain the relaxor and pseudo relaxor behavior.     

The effect of ionisation of silica nanoparticles on their binding to nonionic surfactants in oil–water system: an atomistic molecular dynamic study

ABSTRACT

In this study, the adsorption of nonionic surfactant, triethylene glycol monododecyl ether (C₁₂E₃), on a surface of silica nanoparticle (NP) has been studied with variation in the degree of ionisation (DI) of silica NP using all-atom molecular dynamic simulations in hexadecane–water system. Hydrogen bonding is found to be responsible for the adsorption of C₁₂E₃ on NP, particularly at low DI. We observe that with increasing DI of NP, the amount of adsorption of C₁₂E₃ on NP reduces, which is negligible beyond DI ～ 0.5. The decrease in the adsorption with increasing DI is due to the decrease in the number of hydrogen bonds formed by the silica NP with surfactant molecules. Potential of mean force (PMF) profiles indicate attractive interactions between NP and C₁₂E₃ for DI < 0.5, and for larger DI depletion effect is observed. This work explains the unusual effect of nonionic surfactant on interfacial tension in the presence of silica particles as observed in recent experiments.     

Studies on cationic micelle inhibited transimination reactions of barbituryl-azine-indandione and azine-bis-indandione with semicarbazide

The acid cataylsed transimination reactions of barbituryl-azine-indandione (BAI)and azine-bisindandione (ABI) with semicarbazide are inhibited by n-alkyl trimethylammonium bromides. At a given detergent concentration, the efficiency of inhibition increases with increasing alkyl chain-length of the detergent. Addition of counterions and alcohols increased the cetyltrimethylammonium bromide (CTAB) inhibited rate. Extent of micellar inhibition is reduced by the addition of counterions in the order NO₃^-, > Br^- > Cl^- > SO₄⁼ and by the addition of alcohols in the order n-butanol > n-propanol > ethanol > methanol. Activation parameters for the reactions in the presence of CTAB have been evaluated and compared with those obtained in the absence of detergent.