Zinc protoporphyrin is the predominent fluorescent porphyrin accumulating in erythrocytes as a result of chronic lead absorption or iron-deficiency anemia. Although diagnostic concentrations or thresholds for it in erythrocytes have been inferred, normal adult averages have not been established. We quantitatively assessed average zinc protoporphyrin values during an investigation into the usefu...

We propose a terahertz (far-infrared) circular dichroism-based life-detection technology that may provide a universal and unequivocal spectroscopic signature of living systems regardless of their genesis. We argue that, irrespective of the specifics of their chemistry, all life forms will employ well-structured, chiral, stereochemically pure macromolecules (>500 atoms) as the catalysts with whi...

A monomeric Mn(II) complex has been prepared with the facially-coordinating Tp(Ph2) ligand, (Tp(Ph2) = hydrotris(3,5-diphenylpyrazol-1-yl)borate). The X-ray crystal structure shows three coordinating solvent molecules resulting in a six-coordinate complex with Mn-ligand bond lengths that are consistent with a high-spin Mn(II) ion. Treatment of this Mn(II) complex with excess KO2 at room tempera...

Photoelectron circular dichroism (PECD) is experimentally investigated with chiral specimens with varying amounts of enantiomeric excess (ee). As a prototype, we measure and analyze the photoelectron angular distribution from randomly oriented fenchone molecules in the gas phase that result from ionization with circularly polarized femtosecond laser pulses. The quantification of these measureme...

Conventional circular dichroism (cCD) spectroscopy is a valuable tool for secondary structure analyses of proteins. In recent years, it has been possible to use synchrotrons as light sources for CD, with the technique being known as Synchrotron Radiation Circular Dichroism (SRCD). In this study, the spectra of two proteins, the primarily helical myoglobin and the primarily beta-sheet concanaval...

We have developed a unique binaphthyl-pyrene system 1, whose dihedral angle is reversibly modulated by the addition of Zn(2+). Dihedral angle changes in this system were monitored by using circular dichroism (CD) and by an observed "off-on" fluorescence enhancement in aqueous solution. Owing to these changes, the presence of biologically important Zn(2+) ions in samples can be readily monitored...

CD spectroscopy is an established and valuable technique for examining protein structure, dynamics and folding. Because of its ability to sensitively detect conformational changes, it has important potential for drug discovery, enabling screening for ligand and drug binding, and detection of potential candidates for new pharmaceuticals. The binding of the anti-tumour agent Taxol to the anti-apo...

Diluted magnetic semiconductors (DMSs) are semiconductors alloyed with magnetic elements [1]. The physical properties of these materials can be tuned by both charge and spin, thus, they have great potential of being used in a wide variety of spintronic applications, such as magneto-optical, magneto-electrical, and magneto-transport devices. Spintronics (spin+electronics) is the technology that ...

Cytochromes P-450 and P-448 in microsomal suspensions have been shown to be spectrally distinct by magnetic circular dichroism spectroscopy. Furthermore, this technique can be used to measure induction of these two cytochromes by phenobarbital and 3-methyl-cholanthrene. Magnetic circular dichroism spectroscopy is thus at least as useful as difference spectroscopy for the investigation of P-450 ...