Linear fractional composition operators on H2

If ? is an analytic function mapping the unit diskD into itself, the composition operatorC _? is the operator onH ² given byC _?f=fo?. The structure of the composition operatorC _? is usually complex, even if the function ? is fairly simple. In this paper, we consider composition operators whose symbol ? is a linear fractional transformation mapping the disk into itself. That is, we will assume throughout that $$\varphi \left( z \right) = \frac{{az + b}}{{cz + d}}$$ for some complex numbersa, b, c, d such that ? maps the unit diskD into itself. For this restricted class of examples, we address some of the basic questions of interest to operator theorists, including the computation of the adjoint.     

The magnetic moment of the 10+ isomer in140Ce andE1 transitions inN=82 isotones caused by outer subshell configurations

Using the reaction¹³⁸Ba(α,2n)¹⁴⁰Ce the magnetic moment of the 10 ₁ ⁺ isomer atE _x =3714.7 keV in theN=82 nucleus¹⁴⁰Ce has been determined by means of the TDPAD method toμ=+10.3(4)μ _N . Measuredg-factors in¹⁴⁰Ce are compared to calculations within the shell model with configuration mixing. For the 10 ₁ ⁺ isomer in¹⁴⁰Ce the four proton configuration π(1g ₇ ^2/2 ,2d ₅ ^2/2 ) has been found to be dominant. From theg-factor measurement strong contributions of multiparticle excitations to thegp2d _3/2,π3s ₁ ² or π1h ₁₁ ² shells and admixtures of neutron excitations to the wave function of the 10 ₁ ⁺ state could be excluded. The strongE1γ-branch of the deexcitation of the 10 ₁ ⁺ isomer in¹⁴⁰Ce can be explained by means of small admixtures of configurations which contain the outer subshell excitationsπ2f _7/2 andπ1h _9/2. On this basisE1 transitions experimentally observed in theN=82 nuclei¹⁴⁰Ce,¹⁴¹Pr and¹⁴⁵Eu may be understood.     

Nanoscale organization of the pathogen receptor DC-SIGN mapped by single-molecule high-resolution fluorescence microscopy.

DC-SIGN, a C-type lectin exclusively expressed on dendritic cells (DCs), plays an important role in pathogen recognition by binding with high affinity to a large variety of microorganisms. Recent experimental evidence points to a direct relation between the function of DC-SIGN as a viral receptor and its spatial arrangement on the plasma membrane. We have investigated the nanoscale organization of fluorescently labeled DC-SIGN on intact isolated DCs by means of near-field scanning optical microscopy (NSOM) combined with single-molecule detection. Fluorescence spots of different intensity and size have been directly visualized by optical means with a spatial resolution of less than 100 nm. Intensity- and size-distribution histograms of the DC-SIGN fluorescent spots confirm that approximately 80 % of the receptors are organized in nanosized domains randomly distributed on the cell membrane. Intensity-size correlation analysis revealed remarkable heterogeneity in the molecular packing density of the domains. Furthermore, we have mapped the intermolecular organization within a dense cluster by means of sequential NSOM imaging combined with discrete single-molecule photobleaching. In this way we have determined the spatial coordinates of 13 different individual dyes, with a localization accuracy of 6 nm. Our experimental observations are all consistent with an arrangement of DC-SIGN designed to maximize its chances of binding to a wide range of microorganisms. Our data also illustrate the potential of NSOM as an ultrasensitive, high-resolution technique to probe nanometer-scale organization of molecules on the cell membrane.     

BIOLOGICAL ACTIVITIES OF PHTHALOCYANINES-X. SYNTHESES AND ANALYSES OF SULFONATED PHTHALOCYANINES

Abstract— Synthetic methods to obtain selectively sulfonated metallo phthalocyanines are compared. Both condensation and direct sulfonation procedures lead to mixtures of mono- to tetrasulfonated products which are resolved by reverse phase liquid chromatography in buffered aqueous-methanol. The proportion of sulfonated derivatives is examined as a function of the starting reagents in the case of the condensation method, and as a function of the temperature and reaction time in the case of the direct sulfonation procedure. The number of sulfonate groups per phthalocyanine molecule is determined by oxidative degradation of the phthalocyanine ring followed by quantitative chromatographic analysis of the sulfophthalamide and phthalamide fragments.     

Application of Horner–Emmons Olefination to the Crown-Ether Derivatives

An effective synthetic approach to the preparation of a new crown-ether vinylogs involving the Horner–Emmons olefination of carbonyl precursors with the use of C₂- and C₅-phosphonates was proposed. The effects of the conjugation chain length and the nature of the terminal polar functions in the phosphonate reagent on the yield and process stereoselectivity were discussed.     

THE PHOTOCHEMICAL YIELD OF SINGLET OXYGEN FROM PORPHYRINS IN DIFFERENT STATES OF AGGREGATION

Abstract— Aqueous solutions of hematoporphyrin and hematoporphyrin derivatives were exposed to light. When present in such solutions tryptophan is degraded by a singlet oxygen mechanism. This is true for excitation at 396 nm, where porphyrin monomers have their absorption maximum, as well as for excitation at 360 nm, where porphyrin aggregates seem to absorb strongly. The quantum yield of singlet oxygen production is similar within 25% for excitation at 396 and 360 nm while the fluorescence quantum yield is more than a factor 2 lower for excitation at 360 nm than for excitation at 396 nm. Photoexcitation of the clinically used hematopotophyrin derivatives photofrin I and photofrin II produces singlet oxygen with significantly smaller yields than photoexcitation of hematoporphyrin. Thus, the aggregates present in solutions of photofrin I and photofrin II are of a different nature than those present in aqueous solutions of hematoporphyrin.     

Iodine fluorosulfate reactions with fluorocarbons

Iodine monofluorosulfate has been found to react with fluoroolefins in the absence of a solvent to give the corresponding iodo alkyl fluorosulfates by addition of ?l and ?OSO₂F across the double bond. The observed products were ICF₂CF₂SO₃F, CF₃CFlCF₂SO₃F, and the isomer mixture ICF₂CFClSO₃F and ICFClCF₂SO₃F. Perfluorocyclobutene was unreactive. The iodine fluorosulfate used for this study was synthesized from the reactions of either I₂ or R_fI with ClSO₃F, with both reactions being new routes to this compound. These iodo fluorocarbon fluorosulfates are novel compounds and were characterized by spectroscopy and by formation of the derivatives CF₃CFICFO and ICF₂CFO.     

Charge donation to and dearomatization of benzene attending complexation: DFT estimates of binding energies of TpMXO(L) with benzene, for Tp = hydridotris(pyrazolyl) borate, MXO = MoNO, ReCO, and WNO, and L = ammonia, N-methylimidazole, pyridine, phosphine, methyl isocyanide, and carbon monoxide

By density functional methods we characterize the bonding and charge distribution in complexes of benzene with dearomatizing agents tpReCO(L), tpMoNO(L), and tpWNO(L), where tp = hydrido Tris (pyrazolyl)borate), for a range of ligands L. Our LSDA and B3LYP density functional calculations use the Spartan LACVP+ basis and pseudopotential on Re, Mo, and W and 6-31G* on light atoms. The binding energy is strongly dependent on the nature of the ligand L, being greatest for L = ammonia and N-methylimidazole and weakest for CH3NC and CO. We find a correlation between strength of binding and electron transfer from the dearomatizing agents toward benzene. For the most strongly bound systems we find substantial (up to 500 millielectrons) charge transfer towards benzene, while for the most weakly bound systems charge is withdrawn from benzene. Structural details illustrate the ability of Re, Mo, and W species to dearomatize complexed benzene, which is extensive for all but the most weakly bound species with L = MeNC and CO. Re and W dearomatizing agents, which are computed and observed to form stable complexes with benzene, may be economic alternatives to osmium dearomatizing agents.