Measurement of the spin parameters A and Ann in pp elastic scattering in the 1–3 GeV/c region

We have measured the asymmetry parameter A and the spin correlation parameter A_nn in pp elastic scattering, using the Argonne ZGS polarized proton beam and a polarized proton target. Angular distributions of A and A_nn for |t| ? 0.2 (GeV/c)²wereobtainedateightmomentabetween 1.10 and 2if2.75 GeV/c. We find significant structure in both the energy and t-dependence of A_nn at these energies. At p_lab ≈ 1.34 GeV/cA_nn reaches a very large value of about 0.8–0.9 near θ_cm = 90°.     

Comment on “on the stability of a free-free beam under axial thrust subjected to directional control”

A general method is presented for computing the characteristic multipliers of a linear system of order n with period coefficients, by integrating it over n periods. The calculation of the multipliers in this method is very simple, and in the special case of a reciprocal system the required numerical integration is reduced considerably, in comparison to other solution procedures. An example is given for a third-order system.     

ΔK = 2 transitions in H2CO and D2CO

Weak transitions of the type ΔJ = ± 1, $\text{Δ}\text{K}{}_{\mathrm{a}}\text{= ? 2}$, ΔK_c = ± 3 have been observed in H₂CO and D₂CO by the millimeterwave double resonance method and also by direct absorption with a Stark modulated spectrometer. The addition of these new transitions in a least-squares analysis, in which all previously known microwave and millimeterwave data are also included, results in an improved set of rotational and distortion constants.     

Cyclopolymerisation. 7. Mitt. Die13C-NMR-Spektren von Cyclopolymeren aus N,N-Diallylaminen

Ohne Zusammenfassung     

Synthetic studies on quinine: quinuclidine construction via a ketone enolate regio- and diastereoselective Pd-mediated allylic alkylation

7-Hydroxy-quinine was synthesized by an asymmetric aldol reaction that establishes the C8 and C9 stereochemistry, followed by construction of the 3-vinyl-quinuclidine azabicyclo[2.2.2]octane by C3-C4 ring closure using an intramolecular palladium-mediated allylic alkylation with excellent regio- and diastereoselectivity. This is the first report of a ketone-enolate-stereocontrolled allylic alkylation mediated by palladium. The title compound and a dehydro-quinine analogue were evaluated for antimalarial activity.     

A rapid measurement of flow propagators in porous rocks

NMR flow propagators have been obtained for brine flowing through Bentheimer sandstone using the rapid DiffTrain pulse sequence. In this way, 8 flow propagators at different observation times Delta were acquired in 67 mins, compared to 7 h for the same measurements implemented with conventional pulsed field gradient (PFG) sequences. DiffTrain allows this time saving to be achieved through the acquisition of multiple displacement probability distributions over a range of Delta in a single measurement. If only the propagator moments are required, this experiment time can be further reduced to 9 mins through appropriate sparse sampling at low q values. The propagator moments obtained from DiffTrain measurements with dense and sparse q-space sampling are shown to be equivalent to those obtained from conventional PFG measurements.     

A Review of Patient Adherence to the Recommendation for Voice Therapy

SUMMARY: Voice therapy is a preferred treatment for many voice problems. Many patients referred to voice therapy by their otolaryngologist fail to follow through with the recommendation. Unlike other behavior change therapies, there are no studies documenting the incidence of poor patient attendance in voice therapy. The primary purpose of this study was to document initial patient adherence to the physician's recommendation for voice therapy. A retrospective review of 294 charts was conducted at 2 voice institutions in Atlanta, GA. Reviews included adherence to (1) the physician's referral to the speech-language pathologist and (2) the speech-language pathologist's recommendation for follow-up voice therapy. Thirty-eight percent of patients did not adhere to the physician's recommendation to attend voice therapy. Of those who initiated follow-through, 47% did not return after the initial speech-language pathology evaluation session. There was no significant difference in attendance by gender or by age group. The primary reasons reported for nonattendance were insurance denials, resolution of the problem, and distance to the clinic. The attendance rates described in this study were low but consistent with research published in the fields of otolaryngology, gastroenterology, and psychology. Poor patient attendance is an important area to consider in outcomes research and the cost to healthcare.     

Copper complexes of anionic nitrogen ligands in the amidation and imidation of aryl halides

Copper(I) imidate and amidate complexes of chelating N,N-donor ligands, which are proposed intermediates in copper-catalyzed amidations of aryl halides, have been synthesized and characterized by X-ray diffraction and detailed solution-phase methods. In some cases, the complexes adopt neutral, three-coordinate trigonal planar structures in the solid state, but in other cases they adopt an ionic form consisting of an L 2Cu (+) cation and a CuX 2 (-) anion. A tetraalkylammonium salt of the CuX 2 (-) anion in which X = phthalimidate was also isolated. Conductivity measurements and (1)H NMR spectra of mixtures of two complexes all indicate that the complexes exist predominantly in the ionic form in DMSO and DMF solutions. One complex was sufficiently soluble for conductance measurements in less polar solvents and was shown to adopt some degree of the ionic form in THF and predominantly the neutral form in benzene. The complexes containing dative nitrogen ligands reacted with iodoarenes and bromoarenes to form products from C-N coupling, but the ammonium salt of [Cu(phth) 2] (-) did not. Similar selectivities for stoichiometric and catalytic reactions with two different iodoarenes and faster rates for the stoichiometric reactions implied that the isolated amidate and imidate complexes are intermediates in the reactions of amides and imides with haloarenes catalyzed by copper complexes containing dative N,N ligands. These amidates and imidates reacted much more slowly with chloroarenes, including chloroarenes that possess more favorable reduction potentials than some bromoarenes and that are known to undergo fast dissociation of chloride from the chloroarene radical anion. The reaction of o-(allyloxy)iodobenzene with [(phen) 2Cu][Cu(pyrr) 2] results in formation of the C-N coupled product in high yield and no detectable amount of the 3-methyl-2,3-dihydrobenzofuran or 3-methylene-2,3-dihydrobenzofuran products that would be expected from a reaction that generated free radicals. These data and computed reaction barriers argue against mechanisms in which the haloarene reacts with a two-coordinate anionic copper species and mechanisms that start with electron transfer to generate a free iodoarene radical anion. Instead, these data are more consistent with mechanisms involving cleavage of the carbon-halogen bond within the coordination sphere of the metal.