The red fluorescent protein, DsRed, recently cloned from coral Discosoma sp. has one of the longest fluorescence waves and one of the most complex absorbance spectra among the family of fluorescent proteins. In this work we found that with time DsRed fluorescence decreases under mildly acidic conditions (pH 4.0-4.8) in a pH-dependent manner, and this fluorescence inactivation could be partially...

A silver nanoparticle-modified evanescent field optical fiber sensor based on a MEMS microchannel chip has been successfully fabricated. Experimental results show that the sensor response decreases linearly with increasing concentration of analyte. Over a range of methylene blue concentrations from 0 to 0.4 μmol/mL, the sensor response is linear (R = 0.9496). A concentration variation of 0.1 μm...

The transmission and fluorescence of the compound eye of living, intact blowflies Cuiliphoru erythrocephala, mutant chalky, were studied microspectrophotomettically. Transmission spectra were recorded under four conditions. The fly was either in the normal air environment or in a nitrogen atmosphere, and in both cases the investigated eye was adapted to red and blue light. respectively. The abs...

The transmission and fluorescence of the compound eye of living, intact blowflies Calliphora erythrocephala, mutant chalky, were studied microspectrophotometrically. Transmission spectra were recorded under four conditions. The fly was either in the normal air environment or in a nitrogen atmosphere, and in both cases the investigated eye was adapted to red and blue light, respectively. The abs...

Azobenzenes have been noted for their ability to undergo isomerization between the straight trans isomer and the bent cis isomer with visible light and UV irradiation, respectively. Their photochemically induced isomerization make them highly useful in optical switching devices. Time-dependent density functional theory (TDDFT) can model highly complex molecules like azobenzenes accurately, effi...

This work describes a simple optical method for obtaining, in a single still-capture image, the continuous absorbance spectra of samples at multiple locations of microsystems. This technique uses an unmodified bright-field microscope, an array of microlenses, and a diffraction grating to disperse the light transmitted by samples of 10- to 500-microm dimensions. By analyzing in a single image th...

The Ni4S3 thin films were prepared by chemical bath deposition method. The chemical bath contained nickel sulphate and sodium thiosulfate which supplied the Ni and S ions, respectively. The structure and morphology of the films were studied using X-ray diffraction and atomic force microscopy technique, respectively. Absorbance spectra data of the films were obtained by UV-Vis spectrophotometer....

Magnetized water showed alterations in the electrolyte potential and vibration modes. This study aimed to investigate the effect of magnetic water and physiological solutions on the UV-spectra of tramadol HCl. Distilled water as well as full strength or diluted physiological solutions are magnetized by magnetic disc. Then tramadol HCl was dissolved in each magnetic and in non-magnetic solution ...

Tris(bipyridyl)silicon(iv) was electrochemically reduced in acetonitrile to obtain the UV-vis spectra of its reduced species. Three stable, reversible reduced states (3+, 2+, and 1+) were observed with distinct isosbestic points for each of the redox reactions. The fully oxidized state (4+) is colorless, while the reduced states were green. The absorbance spectra for the three reduced states ar...

a sensitive and selective method using combination of two chemometrics methods, principal component analysis (pca) and artificial neural network (ann), and uv-visible spectroscopy has been developed for the determination of indomethacin (idm) in plasma samples . initially the absorbance spectra were processed using pca to noise reduction and data compression. the scores of these pcs were used a...