A computer code, based upon the existing GUPIX code for PIXE analysis, has been developed to fit X-ray spectra that are excited simultaneously by both XRF and PIXE. Full matrix corrections for both excitation modes are included, and element concentrations are deduced. The code is intended for eventual use in processing spectra from the alpha-particle X-ray spectrometers aboard the Mars Explorat...

alpha-Melanocyte-stimulating hormone (alpha-MSH), a 13-amino acid peptide produced in the brain and pituitary gland, is a regulator of appetite and body weight, and its production is regulated by leptin, a factor that affects bone mass when administered centrally. alpha-MSH acts via melanocortin receptors. Humans deficient in melanocortin receptor 4 (MC4-R) have increased bone mass, and MC4-R h...

In hemoglobin (Hb) Thionville, the substitution of a glutamic acid for the alpha-chain NH2-terminal valine inhibits the cleavage of the initiator methionine which is then acetylated. The elongation of the alpha-chain NH2 terminus modifies the three-dimensional structure of hemoglobin at a region that is known to have an important role in the allosteric regulation of oxygen binding. Relative to ...

The effect of alpha-tocopherol on the structure and phase behavior of dilauroyl-, dimyristoyl-, dipalmitoyl-, and distearoyl-phosphatidylcholines was examined using X-ray diffraction and freeze-fracture electron microscopic methods. A ripple phase was observed in all of the mixtures at temperatures well below the pretransition temperature of the corresponding pure phospholipid. Freeze-fracture ...

High resolution x-ray lithographic studies of cells from chick embryo hearts dried by the CO2 critical point method have been made with soft x-ray radiation of different wavelengths. A marked difference in the relief replica in polymethyl methacrylate (PMMA) resulting from the differential absorption by the dried cells of carbon K alpha radiation at 4.48 nm and broad band synchrotron radiation ...

Glutathione S-transferases (GSTs) form a group of multifunctional isoenzymes that catalyze the glutathione-dependent conjugation and reduction reactions involved in the cellular detoxification of xenobiotic and endobiotic compounds. GST from Xylella fastidiosa (xfGST) was overexpressed in Escherichia coli and purified by conventional affinity chromatography. In this study, the crystallization a...

Structural fluctuations of the apoenzyme form of carboxypeptidase A (EC 3.4.12.2) have been evaluated on the basis of molecular dynamics. The Konnert-Hendrickson refined coordinates of 2437 non-hydrogen atoms of the 307 amino acid residues derived from the X-ray structure of the holoenzyme served as the molecular model together with 548 calculated polar hydrogen atoms and 25 buried solvent mole...

Hematite coated PEG was synthesized by the sonication-calcination method. A variation of Na2CO3 is investigated to know effect on structure and morphology. Characterization samples are using X-ray fluorescence, diffraction, Scanning electron microscopy, color reader techniques. XRF data showed that iron highest element in precursor. The diffraction confirm Fe(OH)3, α-FeOOH, Fe3O4 esta...

The radiation detection systems employed in radioanalytical chemistry laboratories have changed considerably over the past sixty years, with significant improvement realized since the early 1980s. Advancements in the areas of material science, electronics, and computer technology have contributed to the development of more sensitive, reliable, and user-friendly laboratory instruments. The four ...

Localized alpha-particle velocity distribution and density, ion temperature, DT fuel ratio, and internal magnetic field pitch angle can all be potentially diagnosed by a collective Thomson scattering system. Relativistic electron cyclotron calculations and TORAY ray tracing for 6 tesla ITER parameters indicate that 90 GHz is an optimum frequency for this diagnostic. With 400 kW at the plasma an...