160 research outputs found
Nonlinear energy-loss straggling of protons and antiprotons in an electron gas
The electronic energy-loss straggling of protons and antiprotons moving at
arbitrary nonrelativistic velocities in a homogeneous electron gas are
evaluated within a quadratic response theory and the random-phase approximation
(RPA). These results show that at low and intermediate velocities quadratic
corrections reduce significantly the energy-loss straggling of antiprotons,
these corrections being, at low-velocities, more important than in the
evaluation of the stopping power.Comment: 4 pages, 3 figures, to appear in Phys. Rev.
Single-cell transcriptomics uncovers distinct molecular signatures of stem cells in chronic myeloid leukemia
Recent advances in single-cell transcriptomics are ideally placed to unravel intratumoral heterogeneity and selective resistance of cancer stem cell (SC) subpopulations to molecularly targeted cancer therapies. However, current single-cell RNA-sequencing approaches lack the sensitivity required to reliably detect somatic mutations. We developed a method that combines high-sensitivity mutation detection with whole-transcriptome analysis of the same single cell. We applied this technique to analyze more than 2,000 SCs from patients with chronic myeloid leukemia (CML) throughout the disease course, revealing heterogeneity of CML-SCs, including the identification of a subgroup of CML-SCs with a distinct molecular signature that selectively persisted during prolonged therapy. Analysis of nonleukemic SCs from patients with CML also provided new insights into cell-extrinsic disruption of hematopoiesis in CML associated with clinical outcome. Furthermore, we used this single-cell approach to identify a blast-crisis-specific SC population, which was also present in a subclone of CML-SCs during the chronic phase in a patient who subsequently developed blast crisis. This approach, which might be broadly applied to any malignancy, illustrates how single-cell analysis can identify subpopulations of therapy-resistant SCs that are not apparent through cell-population analysis
Dental cell type atlas reveals stem and differentiated cell types in mouse and human teeth
Understanding cell types and mechanisms of dental growth is essential for reconstruction and engineering of teeth. Therefore, we investigated cellular composition of growing and non-growing mouse and human teeth. As a result, we report an unappreciated cellular complexity of the continuously-growing mouse incisor, which suggests a coherent model of cell dynamics enabling unarrested growth. This model relies on spatially-restricted stem, progenitor and differentiated populations in the epithelial and mesenchymal compartments underlying the coordinated expansion of two major branches of pulpal cells and diverse epithelial subtypes. Further comparisons of human and mouse teeth yield both parallelisms and differences in tissue heterogeneity and highlight the specifics behind growing and non-growing modes. Despite being similar at a coarse level, mouse and human teeth reveal molecular differences and species-specific cell subtypes suggesting possible evolutionary divergence. Overall, here we provide an atlas of human and mouse teeth with a focus on growth and differentiation. Unlike human teeth, mouse incisors grow throughout life, based on stem and progenitor cell activity. Here the authors generate single cell RNA-seq comparative maps of continuously-growing mouse incisor, non-growing mouse molar and human teeth, combined with lineage tracing to reveal dental cell complexity.Peer reviewe
Charge identification of highly ionizing particles in desensitized nuclear emulsion using high speed read-out system
Does spatial locative comprehension predict landmark-based navigation?
In the present study we investigated the role of spatial locative comprehension in learning and retrieving pathways when landmarks were available and when they were absent in a sample of typically developing 6- to 11-year-old children. Our results show that the more proficient children are in understanding spatial locatives the more they are able to learn pathways, retrieve them after a delay and represent them on a map when landmarks are present in the environment. These findings suggest that spatial language is crucial when individuals rely on sequences of landmarks to drive their navigation towards a given goal but that it is not involved when navigational representations based on the geometrical shape of the environment or the coding of body movements are sufficient for memorizing and recalling short pathways
Faecalibacterium prausnitzii : from microbiology to diagnostics and prognostics
We thank Dr Xavier Aldeguer and MD David Busquets from the Hospital Dr Josep Trueta (Girona, Spain) and M.D MĂriam Sabat Mir from the Hospital Santa Caterina (Salt, Spain) for their help and critical discussion concerning clinical aspects. This work was partially funded by the Spanish Ministry of Education and Science through the projects SAF2010-15896 and SAF2013-43284-P, which has been co-financed with FEDER funds. Dr Sylvia H Duncan acknowledges support from the Scottish Government Food, Land and People program.Peer reviewedPostprin
Single-cell profiling of human megakaryocyte-erythroid progenitors identifies distinct megakaryocyte and erythroid differentiation pathways
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