Radiochemical Determination of Long-Lived Radionuclides in Proton-Irradiated Heavy Metal Targets: Part II Tungsten.

In this study, proton-irradiated tungsten targets, up to 2.6 GeV, were investigated for the purpose of the experimental cross-section measurements. Radiochemical separation methods were applied to isolate the residual long-lived alpha-emitters 148Gd, 154Dy, and 146Sm and the beta-emitters 129I and 36Cl from proton-irradiated tungsten targets. The molecular plating technique has been applied to prepare 148Gd, 154Dy, and 146Sm samples for alpha-spectrometry. Production cross-sections of 129I and 36Cl were determined by means of accelerator mass spectrometry. The results are compared with theoretical predictions, obtained with the INCL++-ABLA07 codes, showing good agreement for 36Cl and 148Gd, while a factor of 4 difference was observed for 154Dy, similar to the results obtained for tantalum targets.

Radiochemical Determination of Long-Lived Radionuclides in Proton-Irradiated Heavy-Metal Targets: Part I-Tantalum.

In this study, distillation, precipitation, and ion-exchange methods were chosen for the separation of the long-lived ß-emitters 129I, 36Cl and the α-emitters 154Dy, 148Gd, 150Gd, and 146Sm from Ta targets irradiated with protons up to 2.6 GeV to determine their production cross sections. Measurements of 129I/127I and 36Cl/35Cl ratios were performed with accelerator mass spectrometry. After separation of the lanthanides, the molecular plating technique was applied to prepare thin samples to obtain highly resolved α-spectra. Autoradiography and focused ion beam/scanning electron microscopy techniques were used to characterize the lanthanide deposited layer. Experimental cross-section data are compared with theoretical predictions obtained with INCL++ and ABLA07 code, and a satisfactory agreement is observed.

[Should psychotropic drugs be prescribed to adolescents?]. / Peut-on, et comment, prescrire un psychotrope chez l'adolescent?

The prescription of a psychotropic drugs to an adolescent is a high-risk prescription that raises numerous issues, imposing a rigorous evaluation of the expected benefit compared with the results that could be obtained by another approach, and the risk of interference with the spontaneous changes inherent to the process of adolescence. If sedatives, anxiolytics and psychostimulants are proscribed, it is possible in the case of absolute necessity, to prescribe neuroleptics and antidepressants. In this case, the medications should be prescribed in efficacious doses, should be the object of negotiation with the adolescent and his parents, and must never be prescribed at the first consultation nor, in any case, consist of the sole therapeutic intervention. It imposes a regular follow-up of the adolescent to assess compliance and to detect possible suicidal ideation.