The cost of unsafe injections

It provides an estimation of the cost of unsafe injections annually world-wide. Document in pdf format; Acrobat Reader required.

Measurement of the spin asymmetry in the photoproduction of pairs of high- p(T) hadrons at HERMES

We present a measurement of the longitudinal spin asymmetry A(||) in photoproduction of pairs of hadrons with high transverse momentum p(T). Data were accumulated by the HERMES experiment using a 27.5 GeV polarized positron beam and a polarized hydrogen target internal to the HERA storage ring. For h(+)h(-) pairs with p(h(1))(T)>1.5 GeV/c and p(h(2))(T)>1.0 GeV/c, the measured asymmetry is A(||) = -0. 28+/-0.12(stat)+/-0.02(syst). This negative value is in contrast to the positive asymmetries typically measured in deep inelastic scattering from protons, and is interpreted to arise from a positive gluon polarization.

A tightly coupled linear array of perylene, bis(porphyrin), and phthalocyanine units that functions as a photoinduced energy-transfer cascade

We have prepared a linear array of chromophores consisting of a perylene input unit, a bis(free base porphyrin) transmission unit, and a free base phthalocyanine output unit for studies in artificial photosynthesis and molecular photonics. The synthesis involved four stages: (1) a rational synthesis of trans-AB2C-porphyrin building blocks each bearing one meso-unsubstituted position, (2) oxidative, meso,meso coupling of the zinc porphyrin monomers to afford a bis(zinc porphyrin) bearing one phthalonitrile group and one iodophenyl group, (3) preparation of a bis(porphyrin)-phthalocyanine array via a mixed cyclization involving the bis(free base porphyrin) and 4-tert-butylphthalonitrile, and (4) Pd-mediated coupling of an ethynylperylene to afford a perylene-bis(porphyrin)-phthalocyanine linear array. The perylene-bis(porphyrin)-phthalocyanine array absorbs strongly across the visible spectrum. Excitation at 490 nm, where the perylene absorbs preferentially, results in fluorescence almost exclusively from the phthalocyanine (phi(f) = 0.78). The excited phthalocyanine forms with time constants of 2 ps (90%) and 13 ps (10%). The observed time constants resemble those of corresponding phenylethyne-linked dyads, including a perylene-porphyrin (< or = 0.5 ps) and a porphyrin-phthalocyanine (1.1 ps (70%) and 8 ps (30%)). The perylene-bis(porphyrin)-phthalocyanine architecture exhibits efficient light-harvesting properties and rapid funneling of energy in a cascade from perylene to bis(porphyrin) to phthalocyanine.

Evidence for valencelike quark-hadron duality

A newly obtained data sample of inclusive electron-nucleon scattering from both hydrogen and deuterium targets is analyzed. These JLab data span the nucleon resonance region up to four-momentum transfers of 5 (GeV/c)(2). The data are found to follow an average scaling curve. The inclusion of low-momentum transfer data yields a scaling curve resembling deep inelastic neutrino-nucleus scattering data, suggesting a sensitivity to valencelike structure only.