Nucleon structure functions from high energy neutrino interactions

Structure functions obtained from high energy neutrino and antineutrino scattering from an iron target are presented. These were extracted from the combined data of Fermilab experiments E616 and E701; these utilized narrow band beam runs between 1979–1982. The structure functions are used to test the validity of quarkparton model (QPM) predictions and to extract the QCD scale parameter Λ from fits to the Altarelli-Parisi equations.     

A measurement of the neutral current electroweak parameters using the fermilab narrow band neutrino beam

We report a measurement of the electroweak parameters sin₂θ ^w and ? based on the ratios of neutral current to charged current events measured in the Fermilab narrow-band neutrino beam at energies of 30–240 GeV. The data are fully corrected for radiative effects, heavy-quark production, and other effects. The best value for sin₂θ ^w obtained, sin₂θ ^w =0.239±0.011, is consistent with the most recent values fromW andZ production, as well as from other neutrino experiments.     

Transfer of hyperpolarization from long T1 storage nuclei to short T1 neighbors using FLOPSY-8

Nuclei with long T1s are optimal targets for dynamic nuclear polarization (DNP). Therefore, most of the agents used in metabolic imaging and spectroscopy studies are based on carboxylic acid moieties that lack protons, a strong source of dipolar relaxation. Metabolic flux information encoded into spectra of small molecule metabolites in the form of the 13C isotopomer data cannot be accessed using standard 13C hyperpolarization methods because protonated carbons relax too quickly through T1 dipolar relaxation. It is shown here that the longitudinal mixing sequence FLOPSY-8 can be used to transfer polarization from a long T1 storage nucleus to adjacent protonated carbons so that they may be detected with high sensitivity. We demonstrate that FLOPSY-8 allows a direct readout of isotopomer populations in butyrate and glutamate in vitro.     

The convergent syntheses of pyrazinyl and quinoxalinyl phenylmethanones from 2-lithio pyrazines and quinoxalines

Pyrazines and quinoxalines bearing 2-substituents that direct ortho metalation reacted with lithium 2,2,6,6-tetramethylpiperidide to produce 2-substituted-3-lithiopyrazines and quinoxalines. These lithio reagents reacted with N-methoxy-N-methylbenzamide to give good to moderate yields of 3-substituted pyrazinyl or quinoxalinylphenylmethanones. The 3-methylthio substituents of some ketone products were oxidized to methylsulfonyl groups that were susceptible to nucleophilic displacement.     

Transient absorption spectra of 2-hydroxybenzophenone photostabilizers

Transient absorption spectra (400–600 nm) of 2-hydroxybenzophenone and the methyl methacrylate copolymer of 2-hydroxy, 3-allyl, 4,4'-dimethoxybenzophenone following 355 nm excitation (7–480 ps delay) are reported. A short-lived, 435 nm transient (τ ≈ 10 ps in CH₂Cl₂) for both molecules is assigned to the lowest excited singlet before internal proton transfer. Weaker, broad T-T absorption is observed after 480 ps.     

Assessment of angiogenesis: implications for ultrasound imaging

In this paper, the fundamentals of tumor angiogenesis and the implications for ultrasound imaging will be described. Twenty-eight athymic nude mice were implanted with the human melanoma cell lines DB-1 or MW-9 (14 mice/group). Ultrasound contrast agents were injected in the tail veins. Power Doppler and pulse inversion harmonic imaging (PI-HI) was performed (in real time and intermittently). Ultrasound results were compared to immunohistochemical stains for endothelial cells (CD31), vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2). Linear regression analysis indicated statistically significant correlations between percent area stained with COX-2 and with VEGF relative to power Doppler (p<0.05) and intermittent PI-HI (p<0.05) measures of tumor neovascularity in the MW-9 and the DB-1 mice, respectively. Preliminary results from a human trial of the anti-angiogenic drug Angiostatin (Entremed, Rockville, MD) showed tumor volumes increased in two patients, while the vascularity remained virtually unchanged. Conversely, in three patients with diminished tumor volumes vascularity increased by 38%. In conclusion, contrast enhanced ultrasound imaging of tumor neovascularity may provide noninvasive markers of angiogenesis and may become a useful tool for monitoring anti-angiogenic therapies in vivo.