Photodisintegration of aligned deuterons at astrophysical energies using linearly polarized photons

Following the model independent approach to deuteron photodisintegration with linearly polarized $\gamma-$rays, we show that the measurements of the tensor analyzing powers on aligned deuterons along with the differential cross section involve five different linear combinations of the isovector $E1^j_v; j=0,1,2$ amplitudes interfering with the isoscalar $M1_s$ and $E2_s$ amplitudes. This is of current interest in view of the recent experimental finding \cite{blackston1} that the three $E1^j_v$ amplitudes are distinct and also the reported experimental observation \cite{sawatzky} on the front-back (polar angle) asymmetry in the differential cross section.Comment: 12 page

, Nuclear quadrupole moment of 139La from relativistic electronic structure calculations of the electric field gradients in LaF, LaCl, LaBr and LaI

Relativistic coupled cluster theory is used to determine accurate electric field gradients in order to provide a theoretical value for the nuclear quadrupole moment of La139. Here we used the diatomic lanthanum monohalides LaF, LaCl, LaBr, and LaI as accurate nuclear quadrupole coupling constants are available from rotational spectroscopy by Rubinoff [J. Mol. Spectrosc. 218, 169 (2003)]. The resulting nuclear quadrupole moment for La139 (0.200±0.006 barn) is in excellent agreement with earlier work using atomic hyperfine spectroscopy [0.20 (1) barn]. © 2007 American Institute of Physics

Molecular fingerprinting of radiation resistant tumors: Can we apprehend and rehabilitate the suspects?

Radiation therapy continues to be one of the more popular treatment options for localized prostate cancer. One major obstacle to radiation therapy is that there is a limit to the amount of radiation that can be safely delivered to the target organ. Emerging evidence suggests that therapeutic agents targeting specific molecules might be combined with radiation therapy for more effective treatment of tumors. Recent studies suggest that modulation of these molecules by a variety of mechanisms (e.g., gene therapy, antisense oligonucleotides, small interfering RNA) may enhance the efficacy of radiation therapy by modifying the activity of key cell proliferation and survival pathways such as those controlled by Bcl-2, p53, Akt/PTEN and cyclooxygenase-2. In this article, we summarize the findings of recent investigations of radiosensitizing agents in the treatment of prostate cancer

THE DETERMINATION OF CONFORMATION BY NUCLEAR MAGNETIC RESONANCE

Author Institution: Cyanamid European Research InstituteIt has been shown by Karplus and by Conroy that the spin-spin coupling constant between vicinal protons should vary as the square of the cosine of the dihedral angle between the two carbon-hydrogen bonds and their relationship has been shown to be valid for a number of rigid molecules of known conformation. Molecules in which a dihydrobornadiene group is fused to another cyclic system provide a suitable class of compounds whose conformation should be determinable from this relationship, since the dihedral angle between the exo-protons and the adjacent tertiary, protons is $40^\circ$ while that between the endo-protons and the tertiary protons is $80^\circ$, so that the corresponding coupling constants should be 3--4 c/sec and 0 c/sec. We have measured the nuclear magnetic resonance spectra of the following four compounds of this type and thereby determined their conformation. The first two compounds, which are Diels-Alder adducts of eyclopentadiene and benzoquinone, have the endo-conformation thus providing a further example of the stereo-specificity of this type of Diels-Alder reaction. The stereo isomer of II, prepared by enolisation of the primary Diels-Alder adduct, has the mixed endo-exo conformation, while compound IV appears to have the exo-conformation. The spin-coupling constants between the gun protons of the methylene groups show that strain has here increased the tetrahedral angle to between $112^\circ-114^\circ$. [FIGURE