New direct reaction: two-proton knockout from neutron-rich nuclei

The reaction 9Be(28Mg,26Ne+gamma)X has been studied at 82 MeV/nucleon together with two similar cases, 30Mg and 34Si. Strong evidence that the reactions are direct is offered by the parallel-momentum distributions of the reaction residues and by the inclusive cross sections. The pattern of the partial cross sections for 28Mg suggests the presence of correlations. A preliminary theoretical discussion based on eikonal reaction theory and the many-body shell model is presented. The reaction holds great promise for the study of neutron-rich nuclei.     

Femtosecond study of surface structure and composition and time-resolved spectroscopy in metals

Surface structuring and compositioning in aluminum alloy 2024-T3 were demonstrated using a femtosecond pulse laser. Surface nanostructuring was developed as a function of laser parameters and the surface micrographs of the scanning electron microscopy were characterized as a function of incident laser fluence. Surface compositioning was performed by selectively removing the elements on the surface of the sample. Femtosecond studies of highly excited electrons were performed by a pump–probe technique, and the thermalization time was found to be in a range of 1.5–3 ps, increasing with incident fluence. The time-resolved measurement is well matched to the numerical calculation. Received: 6 September 2001 / Accepted: 18 July 2002 / Published online: 25 October 2002 RID="*" ID="*"Corresponding author. Fax: +1-405/744-6811, E-mail: dou@okstate.edu     

Excited-configuration metastable level lifetimes of Cl-like Mn IX and Fe X

Forbidden transitions from levels with 3P and 1D cores in excited configurations of Cl-like Mn IX and Fe X have been isolated using interference filters. The fluorescence decay lifetimes of ions orbiting in a Kingdon ion trap were measured. New relativistic configuration interaction calculations of relevant level lifetimes, to aid the analysis, based on B-spline basis sets, are also presented. Line identifications and experimental lifetimes are Mn IX ((4)D(7/2)-(4)F(9/2)):363(-3/+7) nm; tau(Mn IX3p(4)(3P)3d (4)F(9/2)) = 210+/-42 ms; tau(Fe X,3p(4)(3P)3d (4)F(9/2)) = 85.7+/-9.2 ms; tau(Fe X,3p(4)(3P)3d (4)F(7/2)) = 93+/-30 ms; and tau(Fe X, 3p(4)(1D)3d (2)G(9/2)) = 17.8+/-3.1 ms.     

Copolymerisationen mit Triallylcyanurat, Triallylisocyanurat und Diallylmelamin

Ohne Zusammenfassung     

Real time MRI-ultrasound image guided stereotactic prostate biopsy

To report a technique for target directed transperineal ultrasound guided biopsy using high resolution endorectal MRI images Ultrasound fusion. Two patients presented after external beam irradiation for prostate cancer with a rising PSA. An Endorectal MRI using a 1.5 Tesla scanner was obtained. Subsequently a Transrectal Ultrasound guided biopsy was performed. The Ultrasound probe was fixed to a stepper-stabilizer to provide a reference coordinate system for stereotaxic needle biopsy needle placement. The MRI image set was fused to the Ultrasound images in real time. Abnormal areas determined in the MR images were targeted for biopsy. Recurrent prostate carcinoma was detected pathologically in 3 of 4 stereotactic biopsies. Abnormal areas suspicious for cancer detected on T1 weighted images obtained in a strong field Endorectal MRI scan can be targeted for stereotactic biopsy using Transrectal Ultrasound. This image guide technique may be very useful in directing biopsies.     

Forest management models and combinatorial algorithms: analysis of state of the art

Linear Programming and Mixed Integer Linear Programs have been used for forest planning since the 60's to support decision making on forest harvesting and management. In particular, during the last two decades of forest management there has been an increased interest in spatial issues. Further, new environmental concerns, such as resource sustainability and wildlife protection, impose that increased attention be paid to activities carried out on the ground. Road building needed for access also requires spatial definiton. As a result, more complex models must be used. We discuss the issues which have led to the combinatorial nature of some main forest management problems and the solution algorithms that have been proposed for these problems, including local search heuristics, random search approaches, strengthening of mixed integer model formulations and Lagrangian relaxation. In this survey, we discuss which of the proposed approaches have been used succesfully, the advantages and shortcomings of each and what are still open research problems. This revised version was published online in June 2006 with corrections to the Cover Date.     

Separation of dietary omega‐3 and omega‐6 fatty acids in food by capillary electrophoresis

A lower dietary omega‐6/omega‐3 (n‐6/n‐3) fatty acid ratio (<4) has been shown to be beneficial in preventing a number of chronic illnesses. Interest exists in developing more rapid and sensitive analytical methods for profiling fatty acid levels in foods. An aqueous CE method was developed for the simultaneous determination of 15 n‐3 and n‐6 relevant fatty acids. The effect of pH and concentration of buffer, type and concentration of organic modifier, and additive on the separation was investigated in order to determine the best conditions for the analysis. Baseline separations of the 15 fatty acids were achieved using 40 mM borate buffer at pH 9.50 containing 50 mM SDS, 10 mM β‐cyclodextrin, and 10% acetonitrile. The developed CE method has LODs of <5 mg/L and good linearity (R² > 0.980) for all fatty acids studied. The proposed method was successfully applied to the determination of n‐3 and n‐6 fatty acids in flax seed, Udo® oils and a selection of grass‐fed and grain‐fed beef muscle samples.     

Recoding the Genetic Code with Selenocysteine

Selenocysteine (Sec) is naturally incorporated into proteins by recoding the stop codon UGA. Sec is not hardwired to UGA, as the Sec insertion machinery was found to be able to site‐specifically incorporate Sec directed by 58 of the 64 codons. For 15 sense codons, complete conversion of the codon meaning from canonical amino acid (AA) to Sec was observed along with a tenfold increase in selenoprotein yield compared to Sec insertion at the three stop codons. This high‐fidelity sense‐codon recoding mechanism was demonstrated for Escherichia coli formate dehydrogenase and recombinant human thioredoxin reductase and confirmed by independent biochemical and biophysical methods. Although Sec insertion at UGA is known to compete against protein termination, it is surprising that the Sec machinery has the ability to outcompete abundant aminoacyl‐tRNAs in decoding sense codons. The findings have implications for the process of translation and the information storage capacity of the biological cell.     

The Preparation of Substituted 1(2H)-Isoquinolinones from Polylithiated 2-(2-Methylphenyl)Hydrazinecarboxylic Acid Esters

2-(2-Methylphenyl)hydrazinecarboxylic acid esters were metalated with excess lithium diisopropylamide, and the resulting polyanion-type intermediates were condensed with aromatic esters followed by acid cyclization to the 3-substituted- 1 (2H)-isoquinolinones (isocarbostyrils).