709 resultados para Sint Maarten


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Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia - UL

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We present a study where the energy loss function of Ta2O5, initially derived in the optical limit for a limited region of excitation energies from reflection electron energy loss spectroscopy (REELS) measurements, was improved and extended to the whole momentum and energy excitation region through a suitable theoretical analysis using the Mermin dielectric function and requiring the fulfillment of physically motivated restrictions, such as the f- and KK-sum rules. The material stopping cross section (SCS) and energy-loss straggling measured for 300–2000 keV proton and 200–6000 keV helium ion beams by means of Rutherford backscattering spectrometry (RBS) were compared to the same quantities calculated in the dielectric framework, showing an excellent agreement, which is used to judge the reliability of the Ta2O5 energy loss function. Based on this assessment, we have also predicted the inelastic mean free path and the SCS of energetic electrons in Ta2O5.

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OBJECTIVE: To examine ADHD symptom persistence and subtype stability among substance use disorder (SUD) treatment seekers. METHOD: In all, 1,276 adult SUD treatment seekers were assessed for childhood and adult ADHD using Conners' Adult ADHD Diagnostic Interview for Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; CAADID). A total of 290 (22.7%) participants met CAADID criteria for childhood ADHD and comprise the current study sample. RESULTS: Childhood ADHD persisted into adulthood in 72.8% (n = 211) of cases. ADHD persistence was significantly associated with a family history of ADHD, and the presence of conduct disorder and antisocial personality disorder. The combined subtype was the most stable into adulthood (78.6%) and this stability was significantly associated with conduct disorder and past treatment of ADHD. CONCLUSION: ADHD is highly prevalent and persistent among SUD treatment seekers and is associated with the more severe phenotype that is also less likely to remit. Routine screening and follow-up assessment for ADHD is indicated to enhance treatment management and outcomes.