49 research outputs found
Advancements in the fabrication and characterization of actinide targets for superheavy element production
The heaviest elements can exclusively be produced in actinide-target based nuclear fusion reactions with intense heavy-ion beams. Ever more powerful accelerators deliver beams of continuously increasing intensity, which brings targets of current technology to their limits and beyond. We motivate efforts to produce targets with improved properties, which calls for a better understanding of targets produced by molecular plating, the current standard method. Complementary analytical methods will help shedding more light on their chemical and physical changes in the beam. Special emphasis is devoted to the aspect of the optimum target thickness and the choice of the backing material
α-Synuclein in human cerebrospinal fluid is principally derived from neurons of the central nervous system
The source of Parkinson disease-linked α-synuclein (aSyn) in human cerebrospinal fluid (CSF) remains unknown. We decided to measure the concentration of aSyn and its gradient in human CSF specimens and compared it with serum to explore its origin. We correlated aSyn concentrations in CSF versus serum (QaSyn) to the albumin quotient (Qalbumin) to evaluate its relation to blood–CSF barrier function. We also compared aSyn with several other CSF constituents of either central or peripheral sources (or both) including albumin, neuron-specific enolase, β-trace protein and total protein content. Finally, we examined whether aSyn is present within the structures of the choroid plexus (CP). We observed that QaSyn did not rise or fall with Qalbumin values, a relative measure of blood–CSF barrier integrity. In our CSF gradient analyses, aSyn levels decreased slightly from rostral to caudal fractions, in parallel to the recorded changes for neuron-specific enolase; the opposite trend was recorded for total protein, albumin and β-trace protein. The latter showed higher concentrations in caudal CSF fractions due to the diffusion-mediated transfer of proteins from blood and leptomeninges into CSF in the lower regions of the spine. In postmortem sections of human brain, we detected highly variable aSyn reactivity within the epithelial cell layer of CP in patients diagnosed with a range of neurological diseases; however, in sections of mice that express only human SNCA alleles (and in those without any Snca gene expression), we detected no aSyn signal in the epithelial cells of the CP. We conclude from these complementary results that despite its higher levels in peripheral blood products, neurons of the brain and spinal cord represent the principal source of aSyn in human CSF
Online chemical adsorption studies of Hg, Tl, and Pb on SiO2 and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCA
Online gas-solid adsorption studies with single-atom quantities of Hg, Tl, and Pb, the lighter homologs of the superheavy elements (SHE) copernicium (Cn, Z =112), nihonium (Nh, Z =113), and flerovium (Fl, Z =114), were carried out using short-lived radioisotopes. The interaction with Au and SiO 2 surfaces was studied and the overall chemical yield was determined. Suitable radioisotopes were produced in fusion-evaporation reactions, isolated in the gas-filled recoil separator TASCA, and flushed rapidly to an adjacent setup of two gas chromatography detector arrays covered with SiO 2 (first array) and Au (second array). While Tl and Pb adsorbed on the SiO 2 surface, Hg interacts only weakly and reached the Au-covered array. Our results contribute to elucidating the influence of relativistic effects on chemical properties of the heaviest elements by providing experimental data on these lighter homologs
Doppelimmunfluoreszenzoptischer Nachweis von Antikörpern gegen motorische Endplatten des Skeletmuskels bei Myasthenia gravis
A randomized controlled trial of Internet-based self-help training for recurrent headache in childhood and adolescence
Two different self-help training programs (multimodal cognitive-behavioral training (CBT) and applied relaxation (AR)) presented via the Internet were compared with an educational intervention (EDU) in an RCT. Sixty-five children and adolescents (mean age: 12.7 years) with recurrent headache (at least 2 attacks per month) were each assigned to one of the three treatment conditions. The main outcome variables related to changes in headache frequency, intensity and duration as well as the responder rate (50% reduction of headache frequency) and NNTs. Secondary outcome variables were pain catastrophizing and general well-being (depression, psychopathological symptoms and health-related quality of life). All groups showed significant reduction in headache frequency, duration and pain catastrophizing, but not in headache intensity, depression, psychopathological symptoms or health-related quality of life at post-assessment. NNTs were 2.0 for the comparison CBT and EDU; 5.2 for the comparison of AR and EDU at post-treatment. The highest responder rates at post were from CBT (63%), significantly different compared to AR (32%) and EDU (19%), whereas at follow-up no significant differences were found (CBT: 63%, AR: 56%, EDU: 55%) reflecting in the NNTs. The effects remain stable in headache frequency, pain catastrophizing and psychopathological symptoms across all groups at follow-up assessment. CBT showed the highest within-effect size in headache frequency, duration and pain catastrophizing. The results support the use of Internet programs for pediatric recurrent headache, especially given their accessibility and suitability for children and adolescents. Further studies are needed to improve their quality and efficacy. (C) 2009 Elsevier Ltd. All rights reserved
Internet-Based Self-Help Training for Children and Adolescents with Recurrent Headache: A Pilot Study
We report the results of a randomized controlled trial that compared the efficacy of an internet-based self-help treatment for paediatric headache including chat communication (cognitive-behavioural treatment, CBT) with an internet-based psychoeducation intervention (EDU). In the CBT group, significant pre- to post-treatment decreases were found for headache frequency and pain catastrophizing, but not for headache intensity or duration. In the EDU group none of the variables (frequency, intensity, duration, pain catastrophizing) showed improvement. No significant between group differences were found for headache variables and pain catastrophizing at post-treatment. The patients reported high satisfaction with the internet-based training and a good patient-trainer-alliance. Results were maintained at 6-month follow-up. Due to the small sample size, no general conclusions can be drawn regarding the efficacy of the internet-based training regarding the outcome variables, but the training was well accepted by patients. Further research is necessary to evaluate the therapeutic potential of such interventions
A randomized controlled trial of Internet-based self-help training for recurrent headache in childhood and adolescence
Psychological treatment of recurrent headache in children and adolescents - a meta-analysis
Psychologically based interventions such as relaxation training, biofeedback and cognitive-behavioural therapy are increasingly discussed as options for the treatment of migraine and tension-type headache in children and adolescents. In order to determine the state of evidence regarding the efficacy of these treatments, a meta-analysis of randomized controlled studies was conducted. In a comprehensive literature search including data from 1966 to 2004, 23 studies were found meeting the inclusion criteria. Due to the application of the random effects model, generalization of the results is possible. Specific statistical procedures were used to account for a possible publication bias. Significantly more patients improved to a clinically relevant extent (headache reduction >= 50%) in treatment conditions compared with waiting list conditions (high effect sizes). Long-term stability was also confirmed. The analysed treatments lead to improvement (up to 1 year) in headache status in children and adolescents with primary headache. However, more well-designed studies are needed to support and consolidate the conclusions of this meta-analysis and to compare the effects of psychological treatment with those of prophylactic medical interventions (in migraine), to examine potential differences between treatments, to identify moderators of efficacy and to determine effects of treatment on other health-related variables such as quality of life
