932 research outputs found
Aspects of Cooling at the TRIP Facility
The TriP facility at KVI is dedicated to provide short lived radioactive
isotopes at low kinetic energies to users. It comprised different cooling
schemes for a variety of energy ranges, from GeV down to the neV scale. The
isotopes are produced using beam of the AGOR cyclotron at KVI. They are
separated from the primary beam by a magnetic separator. A crucial part of such
a facility is the ability to stop and extract isotopes into a low energy
beamline which guides them to the experiment. In particular we are
investigating stopping in matter and buffer gases. After the extraction the
isotopes can be stored in neutral atoms or ion traps for experiments. Our
research includes precision studies of nuclear -decay through
- momentum correlations as well as searches for permanent electric
dipole moments in heavy atomic systems like radium. Such experiments offer a
large potential for discovering new physics.Comment: COOL05 Workshop, Galena, Il, USA, 18-23. Sept. 2005, 5 pages, 3
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Cryopreservation of Ovarian Tissue in Pediatric Patients
Cancer treatments improve the survival rate of children and adolescents; however chemo- and radiotherapy result in gonadal damage leading to acute ovarian failure and sterility. Ovarian tissue cryopreservation allows long-term storage of primordial follicles and represents the only possibility of preserving the potential fertility in prepubertal girls. The aim of the present study is to describe our experience in ovarian tissue cryopreservation in 45 pediatric patients. The number of follicles per square millimeter of the overall section area and follicle quality were evaluated histologically. A strong negative correlation was found between age and follicular density in patients both prior to and after chemotherapy (P < 0.0001). Damage in follicular quality, that is, increased oocyte vacuolization and detachment of the oocyte from granulosa cells, was found after chemotherapy. Ovarian tissue cryopreservation, preferably performed before initiation of chemotherapy, should be offered to pediatric patients, including prepubertal girls, at risk of sterility
Phenotypic, morphological, and metabolic characterization of vascular-spheres from human vascular mesenchymal stem cells
The ability to form spheroids under non-adherent conditions is a well-known property of human mesenchymal stem cells (hMSCs), in addition to stemness and multilineage differentiation features. In the present study, we tested the ability of hMSCs isolated from the vascular wall (hVW-MSCs) to grow as spheres, and provide a characterization of this 3D model. hVW-MSCs were isolated from femoral arteries through enzymatic digestion. Spheres were obtained using ultra-low attachment and hanging drop methods. Immunophenotype and pluripotent genes (SOX-2, OCT-4, NANOG) were analyzed by immunocytochemistry and real-time PCR, respectively. Spheres histological and ultrastructural architecture were examined. Cell viability and proliferative capacity were measured using LIVE/DEATH assay and ki-67 proliferation marker. Metabolomic profile was obtained with liquid chromatographyâmass spectrometry. In 2D, hVW-MSCs were spindle-shaped, expressed mesenchymal antigens, and displayed mesengenic potential. 3D cultures of hVW-MSCs were CD44+, CD105low, CD90low, exhibited a low propensity to enter the cell cycle as indicated by low percentage of ki-67 expression and accumulated intermediate metabolites pointing to slowed metabolism. The 3D model of hVW-MSCs exhibits stemness, dormancy and slow metabolism, typically observed in stem cell niches. This culture strategy can represent an accurate model to investigate hMSCs features for future clinical applications in the vascular field
Long-term storage does not impact the quality of cryopreserved human ovarian tissue
Background: Ovarian tissue cryopreservation is an emerging technique, also addressed to very young cancer
patients, for whom it is not possible to perform an ovarian stimulation for oocytes freezing, before gonadotoxic
treatment. In this cases, ovarian tissue must be cryopreserved for a long period of time and it is very important to
know if it maintains fertility function after a long period of storage. Here we aimed to assess the effect of long-term
storage on preservation and viability of cryopreserved human ovarian tissue.
Methods: Descriptive study of three cases of cancer patients whose cryopreserved ovarian tissue remained stored
for 18 years. Long-term stored tissue was examined by histological and immunohistochemical analysis, transmission
electron microscopy, TUNEL assay and LIVE/DEAD viability/citotoxicity test.
Results: Ovarian tissue stored for 18 years showed a good morphology. Follicles presented negative staining for
estrogen and progesterone receptors, positive staining for ki67 in granulosa cells and/or oocytes and for bcl2 in
granulosa cells. Regarding stroma, patch/focal positive expression was found for estrogen receptor and ki67,
diffusely positive expression for progesterone receptor and bcl2. After long-term storage, ultrastructural examination
showed sub-cellular integrity of follicles and interstitial oedema foci. No apoptosis was observable by TUNEL assay.
Stromal cell viability remained >97 % during the culture period.
Conclusion: The evaluation of different aspects o f the tissue provides evidence that the storage time does not impact
on tissue quality and gives hope especially to cancer girls, whose tissues could remain cryopreserved for a very long time
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Beam Based Measurements for Stochastic Cooling Systems at Fermilab
Improvement of antiproton stacking rates has been pursued for the last twenty years at Fermilab. The last twelve months have been dedicated to improving the computer model of the Stacktail system. The production of antiprotons encompasses the use of the entire accelerator chain with the exception of the Tevatron. In the Antiproton Source two storage rings, the Debuncher and Accumulator are responsible for the accumulation of antiprotons in quantities that can exceed 2 x 10{sup 12}, but more routinely, stacks of 5 x 10{sup 11} antiprotons are accumulated before being transferred to the Recycler ring. Since the beginning of this recent enterprise, peak accumulation rates have increased from 2 x 10{sup 11} to greater than 2.3 x 10{sup 11} antiprotons per hour. A goal of 3 x 10{sup 11} per hour has been established. Improvements to the stochastic cooling systems are but a part of this current effort. This paper will discuss Stacktail system measurements and experienced system limitations
Place branding: Are we wasting our time? Report of an AMA special session
Š Emerald Group Publishing Limited.Purpose â The purpose of this paper is to report on a special session entitled âPlace branding: Are we wasting our time?â, held at the American Marketing Associationâs Summer Marketing Educatorsâ conference in 2014. Design/methodology/approach â The report details the outcome of an Oxford-style debate with two opposing teams of two persons â one team supporting and one team opposing the motion. The opening speaker of each team had 10 minutes to put their case across, and the closing speaker had 8 minutes. Teams took to the stand alternately, matching up against each otherâs arguments. Findings â The outcome of the debate points towards a need for place brands to develop as more inclusive and organic entities, in which case it may be best for place practitioners to avoid creating and imposing a place brand and instead help shape it from the views of stakeholder constituencies. This shifts the notion of place branding towards an activity centred on âcurationâ. Originality/value â The use of a competitive debating format as a means for exploring academic ideas and concepts in the place management field
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