DISPA method in the analysis of Mössbauer spectra of metallic glasses

A plot of the DISPersion mode of a pure, ideal Lorentzian line versus the Absorption one (DISPA plot) gives a perfect circle. Non-Lorentzian profiles distort this reference circle in an unambiguous way. A modification of the DISPA method for the lineshape analysis of Mössbauer spectra of amorphous Fe₈₃B₁₇ and Fe₄₀Ni₄₀B₂₀ pointed out convolutions of Gaussian and Lorentzian lines to be somewhat superior. Based on the previous results a construction of a hyperfine field distribution is proposed.     

Triangle group representations and constructions of regular maps

A regular map of type {m,n} is a 2-cell embedding of a graphin an orientable surface, with the property that for any twodirected edges e and e' there exists an orientation-preservingautomorphism of the embedding that takes e onto e', and in whichthe face length and the vertex valence are m and n, respectively.Such maps are known to be in a one-to-one correspondence withtorsion-free normal subgroups of the triangle groups T(2,m,n).We first show that some of the known existence results aboutregular maps follow from residual finiteness of triangle groups.With the help of representations of triangle groups in speciallinear groups over algebraic extensions of Z we then constructivelydescribe homomorphisms from T(2,m,n)=y,z|y^m=zⁿ=(yz)²=1 intofinite groups of order at most c^r where c=c(m,n), such thatno non-identity word of length at most r in x,y is mapped ontothe identity. As an application, for any hyperbolic pair {m,n}and any r we construct a finite regular map of type {m,n} ofsize at most C^r, such that every non-contractible closed curveon the supporting surface of the map intersects the embeddedgraph in more than r points. We also show that this result isthe best possible up to determining C=C(m,n). For r>m thegraphs of the above regular maps are arc-transitive, of valencen, and of girth m; moreover, if each prime divisor of m is largerthan 2n then these graphs are non-Cayley. 2000 Mathematics SubjectClassification: 05C10, 05C25, 20F99, 20H25.     

Application of chemiluminescence immunoassays for steroid hormones in clinical endocrinological investigations in women

Immunoassays based on chemiluminescence for the measurement of serum and plasma steroids (estradiol, estriol, progesterone, testosterone, and cortisol), urinary steroid conjugates (estrone-3-glucuronide, estriol-16α-glucuronide and pregnanediol-3α-glucuronide) and peptide hormones (choriogonadotropin and luteinizing hormone) are surveyed briefly. These immunoassays are simple, robust and valid alternatives to radioimmunoassay. Homogeneous procedures and recent solid-phase assays based on purified specific antibodies, covalently coupled to polymer beads are discussed. Some new results are presented for solid-phase chemiluminescence immunoassays: estradiol is quantified in extracts of serum by using a monoclonal antibody to estradiol with estradiol-6-carboxymethyloxime-aminobutylethyl isoluminol as the marker ligand, and progesterone is quantified in unextracted serum by using a polyclonal antibody to progesterone, progesterone-11-hemisuccinyl-aminobutylethyl isoluminol as the marker ligand, and danazol (17α-pregna-2,4-dien-20-yno[2,3-d]-isoxazol-17-ol) to displace progesterone from serum binding-proteins. Their clinical utility is demonstrated.     

Roothaan INDO CI spin density calculation

Spin densities have been calculated by the Roothaan INDO CI method in the parametrization of Pople and Kaufman. The dependence of the spin densities on both the type and the number of configurations in CI has been followed. Results have been compared with the UHF and spin-projected UHF methods.     

Separation of iron/III/ from manganese/II/ in basalts by solvent extraction

The separation of iron/III/ from manganese/II/ by solvent extraction from hydrochloric acid to the chloroform solution of acetylacetone was applied to the analysis of basalts. The results after single and double separation of iron/III/ from manganese/II/ in basalts are presented.     

PHOTOPHYSICAL PROPERTIES OF PHYCOBILIPROTEINS FROM PHYCOBILISOMES: FLUORESCENCE LIFETIMES, QUANTUM YIELDS, AND POLARIZATION SPECTRA

Abstract— Absorption and fluorescence polarization spectra, as well as absolute fluorescence quantum yields, and lifetimes of phycobiliproteins separated from intact phycobilisomes of Porphyridium cruentum, Nostoc sp. and Fremyella diplosiphon were measured. Two different types of phycoerythrin, in addition to phycocyanin and allophycocyanin, were separated from both Porphyridium cruentum and Nostoc sp. phycobilisomes. They were distinguishable by the shape of their absorption spectra, values of fluorescence quantum yields and their limiting polarization. Phycobilisomes of Fremyella diplosiphon had a type of phycoerythrin that was different from the above kinds. By the use of fluorescence quantum yields and lifetime data, the values of natural lifetimes, the decadic molar extinction coefficients, as well as Förster's critical distances R ₀ for excitation energy transfer, between phycobiliproteins in phycobilisomes, were estimated. The values obtained of Förster's critical distances indicate that for most efficient energy transfer from phycoerythrin to allophycocyanin, the outer layers of Porphyridium cruentum and Nostoc sp. phycobilisomes should be composed of bangiophycean, phycoerythrin and cyanophytan phycoerythrin-II respectively.