Anisotropy dependence of the fluctuation spectroscopy in the critical and gaussian regimes in superconducting NaFe1-xCoxAs single crystals

We investigate thermal fluctuations in terms of diamagnetism and magnetotransport in superconducting NaFe1-xCoxAs single crystals with different doping levels. Results show that in the case of optimal doped and lightly overdoped (x= 0.03, 0.05) crystals the analysis in the critical as well as in the Gaussian fluctuation regions is consistent with the Ginzburg-Landau 3D fluctuation theory. However, in the case of strongly overdoped samples (x >= 0.07) the Ullah-Dorsey scaling of the fluctuation induced magnetoconductivity in the critical region confirms that thermal fluctuations exhibit a 3D anisotropic nature only in a narrow temperature region around T-c(H). This is consistent with the fact that in these samples the fluctuation effects in the Gaussian region above T-c may be described by the Lawrence-Doniach approach. Our results indicate that the anisotropy of these materials increases significantly with the doping level

Gifted children with ADHD: how are they different from non-gifted children with ADHD?

The present study focused on inattention and hyperactivity/impulsivity differences of gifted children with and without attention deficit-hyperactivity disorder (ADHD). Based on clinical assessment utilizing the Anxiety Disorders Interview Schedule for Children (ADISC-IV) and the Wechsler Intelligence Scale for Children—Fourth Edition, attendees of a public outpatient child service (boys = 359, girls = 148), with mean age 10.60 years (SD = 3.08 years), were allocated into four groups: ADHD (N = 350), gifted (N = 15), gifted/ADHD (N = 18), and clinical controls (N = 124). The Strengths and Weaknesses of ADHD-Symptoms and Normal Behavior Scale dimensionally assessed inattention and hyperactivity/impulsivity variations. Compared to the gifted/ADHD group, the ADHD group had higher scores for inattention and comparable scores for hyperactivity/impulsivity. For most symptoms, the ADHD groups (gifted or not) rated higher than the non-ADHD groups (control and gifted without ADHD). Findings appeared to indicate that (i) ADHD is a valid diagnosis among children who are gifted, (ii) gifted children might tend to be less inattentive than non-gifted ADHD children, and (iii) ADHD-gifted children appear to differ from the non-ADHD-gifted children with regard to specific hyperactive and impulsive behaviors. The practical implication of these findings is that clinicians may wish to focus on these symptoms when diagnosing ADHD among children with high intelligence

Investigation of the potentiation of the analgesic effects of fentanyl by ketamine in humans: a double-blinded, randomised, placebo controlled, crossover study of experimental pain[ISRCTN83088383]

<p>Abstract</p> <p>Background</p> <p>Despite preclinical evidence suggesting a synergistic interaction between ketamine and opioids promoting analgesia, several clinical trials have not identified dosing regimens capable of eliciting a benefit in the co-administration of ketamine with opioids.</p> <p>Methods</p> <p>Ten healthy volunteers participated in a double blinded, randomised, placebo controlled, crossover laboratory study in order to determine whether a low dose of ketamine potentiated the antinociceptive effect of fentanyl without causing an increase in sedative effects. A battery of tests was used to assess both nociception and sedation including electrical current, pressure, thermal stimuli, psychometric tests, and both subjective and objective scores of sedation. Target controlled infusions of the study drugs were used. Ketamine and fentanyl were administered alone and in combination in a double-blinded randomised crossover design. Saline was used as the control, and propofol was used to validate the tests of sedation. Cardiovascular and respiratory parameters were also assessed.</p> <p>Results</p> <p>The electrical current pain threshold dose response curve of fentanyl combined with ketamine was markedly steeper than the dose response curve of fentanyl alone. While a ketamine serum concentration of 30 ng/ml did not result in a change in electrical pain threshold when administered alone, when it was added to fentanyl, the combination resulted in greater increase in pain threshold than that of fentanyl administered alone. When nociception was assessed using heat and pressure stimuli, ketamine did not potentiate the anti-nociceptive effect of fentanyl. There was no difference between the sedative effect of fentanyl and fentanyl in combination with ketamine as assessed by both subjective and objective measures of sedation. Cardiovascular and respiratory parameters were unaffected by the study drugs at the doses given.</p> <p>Conclusion</p> <p>A serum concentration of ketamine that did not alter indices of sedation potentiated the antinociceptive effect of fentanyl. This potentiation of antinociception occurred without an increase in sedation suggesting that low steady doses of ketamine (30–120 ng/ml) might be combined with μ opioid agonists to improve their analgesic effect in a clinical setting. (296 words)</p