Measurements of high-energy neutron-induced fission of (nat)Pb and (209)Bi

This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial License 3.0, which permits unrestricted use, distribution, and reproduction in any noncommercial medium, provided the original work is properly citedThe CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV

Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN - N-TOF

The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN - n-TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards

Global patterns of care in advanced stage mycosis fungoides/Sezary syndrome: a multicenter retrospective follow-up study from the Cutaneous Lymphoma International Consortium

ABSTRACT Background Advanced-stage mycosis fungoides (MF)/Sezary syndrome (SS) patients are weighted by an unfavorable prognosis and share an unmet clinical need of effective treatments. International guidelines are available detailing treatment options for the different stages but without recommending treatments in any particular order due to lack of comparative trials. The aims of this second CLIC study were to retrospectively analyze the pattern of care worldwide for advanced-stage MF/SS patients, the distribution of treatments according to geographical areas (USA versus non-USA), and whether the heterogeneity of approaches has potential impact on survival. Patients and methods This study included 853 patients from 21 specialist centers (14 European, 4 USA, 1 each Australian, Brazilian, and Japanese). Results Heterogeneity of treatment approaches was found, with up to 24 different modalities or combinations used as first-line and 36% of patients receiving four or more treatments. Stage IIB disease was most frequently treated by total-skin-electron-beam radiotherapy, bexarotene and gemcitabine; erythrodermic and SS patients by extracorporeal photochemotherapy, and stage IVA2 by polychemotherapy. Significant differences were found between USA and non-USA centers, with bexarotene, photopheresis and histone deacetylase inhibitors most frequently prescribed for first-line treatment in USA while phototherapy, interferon, chlorambucil and gemcitabine in non-USA centers. These differences did not significantly impact on survival. However, when considering death and therapy change as competing risk events and the impact of first treatment line on both events, both monochemotherapy (SHR = 2.07) and polychemotherapy (SHR = 1.69) showed elevated relative risks. Conclusion This large multicenter retrospective study shows that there exist a large treatment heterogeneity in advanced MF/SS and differences between USA and non-USA centers but these were not related to survival, while our data reveal that chemotherapy as first treatment is associated with a higher risk of death and/or change of therapy and thus other therapeutic options should be preferable as first treatment approach

A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers

Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10−8, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers

Some Laser‐Tissue Interactions in 308 nm Excimer Laser Coronary Angioplasty

Some physical concepts of laser‐tissue interactions that occur in 308‐nm excimer laser angioplasty are addressed. Monte Carlo numerical computations were used to analyze the light fluence rate distributions resulting from finite diameter laser beams incident on tissue, as applied by fiber‐optic light delivery catheters. The fluence rate at the inside part of the tissue surface from a 0.2‐mm diameter fiber emitting 308‐nm light, is increased more than twice relative to the incident power density. The light fluence rate distribution inside the tissue spreads very little outside the incident beam diameter. Therefore, the distributions from different fibers in multifiber catheters will not overlap unless the fibers are very close together. The maximum fluence rate decreases with decreasing beam diameters. Ablation of tissue by a 308‐nm excimer laser delivery system in contact with the tissue resulted in a damage zone adjacent to the crater wall, due to expansion of the gaseous debris trapped under the tip of delivery system. In case of contact irradiation, the ablation was more efficient than in case of noncontact irradiation. Direct temperature measurements during excimer laser ablation by an infared (IR) camera showed that temperature accumulation will occur when a sequence of pulses is applied at frequencies of at least 5 Hz. The temperature rise above ambient under circumstances simulating clinical conditions is measured to be 66°± 7°C

Ultrastructural characterization of bovine umbilical cord blood cells Caracterização ultra-estrutural das células sanguíneas do cordão umbilical bovino

The umbilical cord blood (UCB) is an important source of pluripotent stem cells, which motivated researches on ontogeny and transplantation. The morphological characterization of umbilical cord cells is the first step to establish subsequent experiments on these areas. Although some information on humans can be found, no data on UCB is available for bovines. Therefore, this work is the first attempt to conduct an ultrastructural characterization of bovine umbilical cord blood. Blood was collected from the umbilical cord of twenty fetuses by punction of the umbilical vein. Samples were processed for whole leucocytes observation by centrifugation and the buffy coat was collected. Cells were washed and pelleted and prepared according to the standard protocol of the transmission electron microscopy. The presence of cells with morphologic characteristics compatible with the precursors from the erythrocytic, neutrophilic, eosinophilic, basophilic, and lymphocytic lineages was observed. Atypical cells with peculiar morphological features, strongly similar to apoptotic cells, were seen. Bovine neutrophils with three types of cytoplasmic granules were also found in the blood. The ultrastructural characteristics of observed bovine UCB cells where similar to those found in other species, suggesting that bovines could possibly constitute an experimental model for approaches on UCB cells research.<br>O sangue de cordão umbilical (SCU) é uma importante fonte de células progenitoras pluripotentes, que motiva pesquisas em ontogenia e transplantes. A caracterização morfológica das células de cordão umbilical é o primeiro passo para se estabelecer experimentos subsequentes nessas áreas. Embora algumas informações sobre SCU em humanos possam ser encontradas, não existe nenhuma informação disponível sobre elas em bovinos. Portanto, este trabalho é a primeira tentativa de se conduzir uma caracterização ultra-estrutural do sangue de cordão umbilical bovino. O sangue foi coletado do cordão umbilical de 20 fetos por punção da veia umbilical. As amostras foram processadas para observação dos leucócitos totais por centrifugação pela coleta do botão leucocitário. As células foram lavadas, peletizadas e preparadas de acordo com protocolo padrão para microscopia eletrônica de transmissão. A presença de células com características morfológicas compatíveis com precursores das linhagens eritrocítica, neutrofílica, eosinofílica, basofílica e linfocítica foram observadas. Células atípicas com características morfológicas peculiares muito semelhantes a c��lulas em apoptose foram observadas. No sangue do cordão umbilical também foi encontrado neutrófilos bovinos apresentando três tipos de grânulos citoplasmáticos. As características ultraestruturais do SCU bovino foram semelhantes às encontradas em outras espécies, sugerindo que esta espécie possa servir como modelo experimental para abordagens em pesquisa sobre sangue de cordão umbilical