54 research outputs found

    Erosion Study of Tungsten Carbide films under 100 keV Kr+ ion irradiation

    Full text link
    Tungsten carbide (WC) stands out as a crucial material for exploration in extreme environments due to its resistance to radiation and impressive mechanical strength. Widely utilized in cutting tools, high-wear components, and as a potential contender for plasma-facing material in nuclear reactors, WC's erosion behavior under surrogate irradiations is a subject of investigation. In the present work, WC films were synthesized at two different substrate temperatures of 400 K and 600 K using RF sputtering and were then irradiated with 100 keV Kr1+ ions at a fluence of 1x1017 ions/cm2. The crystalline phases of as deposited WC films were confirmed by glancing incidence X-ray diffraction (GIXRD) measurements. Rutherford Backscattering Spectrometry (RBS) was employed to determine the thicknesses of pristine samples and the sputtering rate by measuring the difference in the areal densities of the pristine and irradiated films. The erosion rate of both types of films was found to be ~ 1.6 atoms per incident Kr+ ion. These findings contribute to a foundational comprehension of the radiation tolerance behavior of WC thin films, crucial for their performance in the demanding conditions of extreme radiation.Comment: 10 pages, 5 figure

    An atypical adenomatoid odontogenic tumour in the mandible: a report of a paediatric case

    Get PDF
    An adenomatoid odontogenic tumour (AOT) is a rare odontogenic tumour that is often misdiagnosed as an odontogenic cyst. To acquire additional information about AOT, all reports regarding AOT that had been cited in ‘Pub Med’ since 1990 onwards were reviewed. AOT accounts for about 1–9% of all odontogenic tumours. It is predominantly found in young and female patients, is located more often in the maxilla, and in most cases is associated with an unerupted permanent tooth. The differential diagnosis between AOT and other odontogenic tumours such as ameloblastoma should be well made to avoid extensive ablative surgery. However, AOT frequently resembles other odontogenic lesions such as dentigerous cysts or ameloblastoma. Immunohistochemically, AOT is characterized by positive reactions with certain cytokeratins. For illustration a rare case of an AOT in the mandible is presented that had atypical findings such as buccolingual cortical perforation and resorption with displacement of adjoining teeth.Keywords: adenomatoid odontogenic tumor, dentigerous cyst, odontogenic tumor, paediatric cas

    Plant Species Diversity along an Altitudinal Gradient of Bhabha Valley in Western Himalaya

    Get PDF
    The present study highlights the rich species diversity of higher plants in the Bhabha Valley of western Himalaya in India. The analysis of species diversity revealed that a total of 313 species of higher plants inhabit the valley with a characteristic of moist alpine shrub vegetation. The herbaceous life forms dominate and increase with increasing altitude. The major representations are from the families Asteraceae, Rosaceae, Lamiaceae and Poaceae, suggesting thereby the alpine meadow nature of the study area. The effect of altitude on species diversity displays a hump-shaped curve which may be attributed to increase in habitat diversity at the median ranges and relatively less habitat diversity at higher altitudes. The anthropogenic pressure at lower altitudes results in low plant diversity towards the bottom of the valley with most of the species being exotic in nature. Though the plant diversity is less at higher altitudinal ranges, the uniqueness is relatively high with high species replacement rates. More than 90 % of variability in the species diversity could be explained using appropriate quantitative and statistical analysis along the altitudinal gradient. The valley harbours 18 threatened and 41 endemic species, most of which occur at higher altitudinal gradients due to habitat specificit

    Mesodermal fate decisions of a stem cell: the Wnt switch

    Get PDF
    Stem cells are a powerful resource for cell-based transplantation therapies in osteodegenerative disorders, but before some kinds of stem cells can be applied clinically, several aspects of their expansion and differentiation need to be better controlled. Wnt molecules and members of the Wnt signaling cascade have been ascribed a role in both these processes in vitro as well as normal development in vivo. However some results are controversial. In this review we will present the hypothesis that both canonical and non-canonical signaling are involved in mesenchymal cell fate regulation, such as adipogenesis, chondrogenesis and osteogenesis, and that in vitro it is a timely switch between the two that specifies the identity of the differentiating cell. We will specifically focus on the in vitro differentiation of adipocytes, chondrocytes and osteoblasts contrasting embryonic and mesenchymal stem cells as well as the role of Wnts in mesenchymal fate specification during embryogenesis

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

    Get PDF
    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

    Get PDF
    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Ecological Characterization of High Altitude Himalayan Landscapes in the Upper Satluj River Watershed, Kinnaur, Himachal Pradesh, India

    No full text
    The Indian Remote Sensing (IRS) LISS III satellite imagery was used to classify three landscapes in the upper Satluj river watershed in Kinnaur region of western Himalaya viz. Nichar, Kalpa and Pooh. These landscapes representing different eco-climatic zones were subjected to landscape ecological analysis and various landscape composition, patch and edge characteristic metrics were computed to find the extent of fragmentation in the natural vegetation. The natural vegetation comprised of forests (10.24%), grasslands (31.04%) and scrublands (2.95%) as the landscape elements (LSE). These LSEs were further segregated into different LSE types based on the dominant species of plant communities in the landscapes. These LSE types were surveyed for species diversity in the three landscapes. The total landscape area (TLA) covered by natural vegetation in Nichar, Kalpa and Pooh landscapes was calculated to be 651.42, 529.02 and 1,673.72 km2 making the total area covered with natural vegetation in the district as 2,854.16 km2. The Pooh block, lying in the east of the district, though covered the largest area of the landscape, was poor in terms of landscape composition as compared to the Nichar block which was rich in landscape elements as suggested by the diversity measures. The extent of fragmentation was found to be highest in Nichar. The Nichar landscape was observed to be having higher mean values of species diversity than other blocks which is consistent with the trends observed with patches diversity. This was in contrast to the Pooh landscape where the patch diversity as well as the species diversity was the lowest. Thus, an ecological analysis utilizing landscape metrics and biodiversity field sampling of vegetation, was attempted for such heterogenous landscapes in high altitudes of Himalaya, which provided a baseline data for the management and conservation of these virgin mountainous area

    Long-term ecological and biodiversity monitoring in the western Himalaya using satellite remote sensing

    No full text
    The IPCC in its Fourth Assessment Report (AR4) described the Himalayan Region as data-deficient in terms of climate monitoring. This is a serious impediment to global research initiatives and thus necessitates long-term ecological monitoring (LTEM) across the Himalaya. Being governed by low temperature conditions, the high-altitude regions in Himalaya are more responsive to changing environmental conditions and hence serve as better indicators. We identified few Protected Areas (PAs) and selected forest core area and ecotones along the temperate, sub-alpine, alpine and cold desert ecosystems in Himachal Pradesh to establish a network of permanent monitoring plots (PMPs). Land and vegetation cover map of three selected PAs has been prepared using Landsat TM satellite data. Among the 10 PMPs, the temperate and tree line forests in the GHNP were found to have the highest tree diversity with Taxus wallichiana showing good stand density and regeneration. The soil pH was found to be higher for cold desert and lower for tree line forests and alpine meadows. Soil total carbon and nitrogen contents ranged from 1.08% to 13.37% and 0.094% to 1.14% respectively. It was observed that the herbs diversity showed a positive trend with increasing soil carbon and nitrogen concentrations. Satellite remote sensing proves to be a useful tool in an LTEM study, including biodiversity assessment and climate change research in complex terrains such as the Himalaya
    • …
    corecore