1,011 research outputs found
Meson-induced correlations of nucleons in nuclear Compton scattering
The non-resonant (seagull) contribution to the nuclear Compton amplitude at
low energies is strongly influenced by nucleon correlations arising from meson
exchange. We study this problem in a modified Fermi gas model, where nuclear
correlation functions are obtained with the help of perturbation theory. The
dependence of the mesonic seagull amplitude on the nuclear radius is
investigated and the influence of a realistic nuclear density on this amplitude
is dicussed. We found that different form factors appear for the static part
(proportional to the enhancement constant ) of the mesonic seagull
amplitude and for the parts, which contain the contribution from
electromagnetic polarizabilities.Comment: 15 pages, Latex, epsf.sty, 9 eps figures
European Conditional Marketing Authorization in a Rapidly Evolving Treatment Landscape: A Comprehensive Study of Anticancer Medicinal Products in 2006-2020
Since 2006, the European conditional marketing authorization (CMA) aims to facilitate timely patient access to medicinal products for which there is an unmet medical need by accepting less comprehensive data than normally required. The granting of CMA requires a positive benefit-risk balance, unmet medical needs to be fulfilled, likely submission of comprehensive data postauthorization, and the benefit of immediate availability to outweigh the risks of data noncomprehensiveness. Since its first use, more than half of all CMAs represent (hemato-)oncology indications. Therefore, we aimed to investigate the conditions in which CMA has been applied for anticancer medicinal products and whether they have changed over time. We retrospectively assessed the European public assessment reports of the 30 anticancer medicinal products granted CMA in 2006-2020 (51% of all 59 CMAs). Comparison of 2006-2013 to 2014-2020 highlighted increased proportions of proactively requested CMAs (+40%), medicinal products that addressed unmet medical needs by providing a major therapeutic advantage over authorized treatments (+38%), and orphan designated indications (+32%). In contrast, it showed decreased proportions of medicinal products for which a scientific advisory group was consulted (-55%) and phase III randomized controlled trial data were available (-38%). This suggests that applicants and the European Medicines Agency have learned how to use the CMA as a regulatory tool, among others, through better planning and proactive interaction. However, the increasing number of granted CMAs complicates the establishment of unmet medical need and the benefit-risk balance, especially in crowded indications and when only phase II uncontrolled trials are available
Klimaatverandering en de functies van het landelijk gebied : resultaten van vier jaar klimaatonderzoek
Vier thema's komen in deze brochure aan bod: koolstofvastlegging in bos en landbouw; emissies van lachgas en methaan uit de landbouw; landgebruik als actor en reactor in het klimaatsysteem; klimaatverandering en het landelijk gebied: een integrale kijk. Uitleg over een actueel onderwerp, aan de hand van 31 vrage
Identification of potential non-invasive biomarkers in diastrophic dysplasia.
Diastrophic dysplasia (DTD) is a recessive chondrodysplasia caused by pathogenic variants in the SLC26A2 gene encoding for a cell membrane sulfate/chloride antiporter crucial for sulfate uptake and glycosaminoglycan (GAG) sulfation. Research on a DTD animal model has suggested possible pharmacological treatment approaches. In view of future clinical trials, the identification of non-invasive biomarkers is crucial to assess the efficacy of treatments. Urinary GAG composition has been analyzed in several metabolic disorders including mucopolysaccharidoses. Moreover, the N-terminal fragment of collagen X, known as collagen X marker (CXM), is considered a real-time marker of endochondral ossification and growth velocity and was studied in individuals with achondroplasia and osteogenesis imperfecta. In this work, urinary GAG sulfation and blood CXM levels were investigated as potential biomarkers for individuals affected by DTD. Chondroitin sulfate disaccharide analysis was performed on GAGs isolated from urine by HPLC after GAG digestion with chondroitinase ABC and ACII, while CXM was assessed in dried blood spots. Results from DTD patients were compared with an age-matched control population. Undersulfation of urinary GAGs was observed in DTD patients with some relationship to the clinical severity and underlying SLC26A2 variants. Lower than normal CXM levels were observed in most patients, even if the marker did not show a clear pattern in our small patient cohort because CXM values are highly dependent on age, gender and growth velocity. In summary, both non-invasive biomarkers are promising assays targeting various aspects of the disorder including overall metabolism of sulfated GAGs and endochondral ossification
Search for the decay
We search for radiative decays into a weakly interacting neutral
particle, namely an invisible particle, using the produced through the
process in a data sample of
decays collected by the BESIII detector
at BEPCII. No significant signal is observed. Using a modified frequentist
method, upper limits on the branching fractions are set under different
assumptions of invisible particle masses up to 1.2 . The upper limit corresponding to an invisible particle with zero mass
is 7.0 at the 90\% confidence level
First observations of hadrons
Based on events collected with
the BESIII detector, five hadronic decays are searched for via process
. Three of them, ,
, and are observed for the first
time, with statistical significances of 7.4, , and
9.1, and branching fractions of ,
, and ,
respectively, where the first uncertainties are statistical and the second
systematic. No significant signal is observed for the other two decay modes,
and the corresponding upper limits of the branching fractions are determined to
be and at 90% confidence level.Comment: 17 pages, 16 figure
- …