203 research outputs found

    Investigation of complete and incomplete fusion in 7^{7}Li+124^{124}Sn reaction around Coulomb barrier energies

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    The complete and incomplete fusion cross sections for 7^{7}Li+124^{124}Sn reaction were measured using online and offline characteristic Îł\gamma-ray detection techniques. The complete fusion (CF) cross sections at energies above the Coulomb barrier were found to be suppressed by ∌\sim 26 \% compared to the coupled channel calculations. This suppression observed in complete fusion cross sections is found to be commensurate with the measured total incomplete fusion (ICF) cross sections. There is a distinct feature observed in the ICF cross sections, i.e., t\textit{t}-capture is found to be dominant than α\alpha-capture at all the measured energies. A simultaneous explanation of complete, incomplete and total fusion (TF) data was also obtained from the calculations based on Continuum Discretized Coupled Channel method with short range imaginary potentials. The cross section ratios of CF/TF and ICF/TF obtained from the data as well as the calculations showed the dominance of ICF at below barrier energies and CF at above barrier energies.Comment: 9 pages, 8 figure

    Atypical Mesenchymal Stromal Cell Responses to Topographic Modifications of Titanium Biomaterials Indicate Cytoskeletal- and Genetic Plasticity-Based Heterogeneity of Cells

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    Titanium (Ti) is widely used as a biomaterial for endosseous implants due to its relatively inert surface oxide layer that enables implanted devices the ability of assembling tissue reparative components that culminate in osseointegration. Topographic modifications in the form of micro- and nanoscaled structures significantly promote osseointegration and enhance the osteogenic differentiation of adult mesenchymal stromal cells (MSCs). While the biological mechanisms central to the differential responses of tissues and cells to Ti surface modifications remain unknown, adhesion and morphological adaptation are amongst the earliest events at the cell-biomaterial interface that are highly influenced by surface topography and profoundly impact the regulation of stem cell fate determination. This study correlated the effects of Ti topographic modifications on adhesion and morphological adaptation of human MSCs with phenotypic change. The results showed that modified Ti topographies precluded the adhesion of a subset of MSCs while incurring distinct morphological constraints on adherent cells. These effects anomalously corresponded with a differential expression of stem cell pluripotency and Wnt signalling-associated markers on both modified surfaces while additionally differing between hydrophobic and hydrophilic surface modifications—though extent of osteogenic differentiation induced by both modified topographies yielded similarly significant higher levels of cellular mineralisation in contrast to polished Ti. These results suggest that in the absence of deposited proteins and soluble factors, both modified topographies incur the selective adhesion of a subpopulation of progenitors with relatively higher cytoskeletal plasticity. While the presence of deposited proteins and soluble factors does not significantly affect adherence of cells, nanotopographic modifications enhance expression of pluripotency markers in proliferative conditions, which are conversely overridden by both modified topographies in osteogenic inductive conditions. Further deciphering the mechanisms underlying cellular selectivity and Ti topographic responsiveness will improve our understanding of stem cell heterogeneity and advance the potential of MSCs in regenerative medicine.</jats:p

    Wounds : an overlooked burden (Part 2) – Wound treatment : a daunting decision

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    Various types of wounds are encountered daily in medical practice, and due to the numerous treatment options available on the market, making the most appropriate choice of treatment may be a rather daunting decision. The wound treatment should not inconvenience the patient to the point that the wound care becomes compromised. It is for this reason that a proper assessment of the wound status be conducted in order to select an appropriate treatment intervention or dressing type, as this will directly impact the way in which the wound heals. This article is based on the expertise of three active wound care practitioners and aims to provide guidance to clinicians when providing primary wound care. The downloadable tables can be printed and used as reference materials in daily practice.https://journals.co.za/journal/mp.sagphttps://journals.co.za/journal/mp.sagpam2022Pharmacolog

    Wounds : an overlooked burden (Part 3) - Chronic wounds : a conundrum of complications

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    Wound healing is a complex process which may be hindered by a range of interfering factors, especially in patients with underlying pathologies. This results in the formation of chronic, non-healing wounds which subject the patient to significant discomfort while placing strain on the resources of any medical system. Primary healthcare practitioners are often the first to encounter chronic wounds of various aetiologies. This article provides guidelines on the assessment, wound bed preparation and treatment of various types of chronic wounds, which have been summarised into downloadable reference tables for use in everyday practice.National Research Foundation – Blue Skies Granthttp://www.sagpj.co.za/index.php/SAGPJPharmacolog

    Systematic investigation of channel coupling effects on elastic, inelastic and neutron transfer channels in 6^6Li+159^{159}Tb

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    Elastic scattering angular distribution for weakly bound nucleus 6^{6}Li on the deformed rare earth 159^{159}Tb target nucleus has been measured at energies around the Coulomb barrier. The elastic scattering cross sections for this reaction consist of inelastic contributions from low lying excited states of 159^{159}Tb. The pure elastic cross-sections have been extracted from the admixture of elastic and inelastic data. The optical model potential parameters for the system have been obtained from the extracted pure elastic scattering cross sections. Coupled channel calculations have been performed with this set of potential parameters, to compare the theoretical and experimental inelastic scattering cross sections. The work has been extended to obtain the spectroscopic factor for 158^{158}Tb+n configuration from the experimental 1n-pickup data

    Evidence for transfer followed by breakup in 7Li + 65Cu

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    The observation of a large cross-section for the alpha + d channel compared to breakup into the alpha + t channel from an exclusive measurement for the 7Li+65Cu system at 25 MeV is presented. A detailed analysis of the angular distribution using coupled channels Born approximation calculations has provided clear evidence that the observed alpha + d events arise from a two step process, i.e. direct transfer to the 2.186 MeV (3+) resonance in the alpha + d continuum of 6Li followed by breakup, and are not due to final state interaction effects.Comment: 12 pages, 3 figures, To be published in Phys. Letts.

    COVID‑19 pneumonia imaging follow‑up: when and how? A proposition from ESTI and ESR

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    Abstract This document from the European Society of Thoracic Imaging (ESTI) and the European Society of Radiology (ESR) discusses the role of imaging in the long-term follow-up of COVID-19 patients, to define which patients may benefit from imaging, and what imaging modalities and protocols should be used. Insights into imaging features encountered on computed tomography (CT) scans and potential pitfalls are discussed and possible areas for future review and research are also included. Key Points ‱ Post-COVID-19 pneumonia changes are mainly consistent with prior organizing pneumonia and are likely to disappear within 12 months of recovery from the acute infection in the majority of patients. ‱ At present, with the longest series of follow-up examinations reported not exceeding 12 months, the development of persistent or progressive fibrosis in at least some individuals cannot yet be excluded. ‱ Residual ground glass opacification may be associated with persisting bronchial dilatation and distortion, and might be termed “fibrotic-like changes” probably consistent with prior organizing pneumonia.publishedVersio
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