LIGHT-MEDIATED CYCLIZATION OF (E)-3-(5-[6-HYDROXY-7-METHOXY] BENZOFURANYL)PROPENOIC ACID, A WATER-SOLUBLE PRECURSOR OF 8-METHOXYPSORALEN

The title compound is a stable, water-soluble "pro-drug" for 8-methoxypsoralen, which converts to psoralen upon photolysis with UVA light. The process involves the photolytic formation of a cis isomer that lactonizes in a dark reaction.     

Photochemistry and Photobiology of lmidazole-4(5)-Methylidene Malonic Acid: An Analog of Both E- and Z-Urocanic Acid*

Imidazole-4(5)-methylidene malonic acid (IMMA) may be thought of as having its imidazole and carboxyl functionalities permanently fixed in a configuration that is simultaneously analogous to both E- (trans) and Z- (cis) urocanic acid (UA). Because the UA isomers affect the photoinactivation of bacteriophage single-stranded DNA differently (E-UA increases and Z-UA decreases viral DNA inactivation), IMMA was similarly tested and was found to change the inactivation rate by a factor of 0.43, which is intermediate between the values for E- and Z-UA (1.6 and 0.014, respectively). The IMMA likewise sensitizes double-stranded DNA by a factor of 10.3 compared to a value of 13 for UA. In several ways the effects of IMMA parallel the distinctive effects of UA on the UV inactivation of single- and double-stranded DNA, including the ability to prevent the formation of cyclobutane pyrimidine dimers in irradiated single-stranded DNA and to sensitize a large increase in the formation of those dimers in irradiated double-stranded DNA. The IMMA photodecarboxylates to UA with a low quantum efficiency (ca 1 × 10^?3) and photochemically binds to calf-thymus DNA.     

Compatibility and optoelectronic of ZnSe nano crystalline thin film

We report the room temperature synthesis of zinc selenide (ZnSe) nano crystalline thin film on quartz by using a relatively simple and low cost closed space sublimation process (CSSP). The compatibility of the prepared thin films for optoelectronic applications was assessed by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscope (SEM), Raman spectroscopy, photoluminescence, and Fourier transform infrared spectroscopy (FT-IR). The XRD confirmed that the films were polycrystalline with the preferential orientation along the (111) plane corresponding to the cubic phase (2θ = 27.28 ). The AFM indicated that the ZnSe film presented a smooth and compact morphology with RMS roughness 19.86 nm. The longitudinal optical phonon modes were observed at 247 cm 1 and 490 cm 1 attributed to the cubic structured ZnSe. The Zn-Se stretching band was confirmed by the FT-IR. The microstructure and compositional analysis was made with the SEM. The grain size, dislocation density, and strain calculated were co-related. All these properties manifested a good quality, high stability, finely adhesive, and closely packed structured ZnSe thin film for optoelectronic applications.     

Geometrothermodynamics of five dimensional black holes in Einstein–Gauss–Bonnet theory

We investigate the thermodynamic properties of 5D static and spherically symmetric black holes in (i) Einstein–Maxwell–Gauss–Bonnet theory, (ii) Einstein–Maxwell–Gauss–Bonnet theory with negative cosmological constant, and in (iii) Einstein–Yang–Mills–Gauss–Bonnet theory. To formulate the thermodynamics of these black holes we use the Bekenstein–Hawking entropy relation and, alternatively, a modified entropy formula which follows from the first law of thermodynamics of black holes. The results of both approaches are not equivalent. Using the formalism of geometrothermodynamics, we introduce in the manifold of equilibrium states a Legendre invariant metric for each black hole and for each thermodynamic approach, and show that the thermodynamic curvature diverges at those points where the temperature vanishes and the heat capacity diverges.     

Biogenic Synthesis of Silver Nanoparticles Using Catharanthus roseus and Its Cytotoxicity Effect on Vero Cell Lines

Background: Type 2 diabetes mellitus (DM2) is a chronic and sometimes fatal condition which affects people all over the world. Nanotherapeutics have shown tremendous potential to combat chronic diseases—including DM2—as they enhance the overall impact of drugs on biological systems. Greenly synthesized silver nanoparticles (AgNPs) from Catharanthus roseus methanolic extract (C. AgNPs) were examined primarily for their cytotoxic and antidiabetic effects. Methods: Characterization of C. AgNPs was performed by UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and atomic force microscopy (AFM). The C. AgNPs were trialed on Vero cell line and afterwards on an animal model (rats). Results: The C. AgNPs showed standard structural and functional characterization as revealed by FTIR and XRD analyses. The zetapotential analysis indicated stability while EDX analysis confirmed the formation of composite capping with Ag metal. The cytotoxic effect (IC50) of C. AgNPs on Vero cell lines was found to be 568 g/mL. The animal model analyses further revealed a significant difference in water intake, food intake, body weight, urine volume, and urine sugar of tested rats after treatment with aqueous extract of C. AgNPs. Moreover, five groups of rats including control and diabetic groups (NC1, PC2, DG1, DG2, and DG3) were investigated for their blood glucose and glycemic control analysis. Conclusions: The C. AgNPs exhibited positive potential on the Vero cell line as well as on experimental rats. The lipid profile in all the diabetic groups (DG1-3) were significantly increased compared with both of the control groups (p < 0.05). The present study revealed the significance of C. AgNPs in nanotherapeutics.