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Sökning: WFRF:(Tiwari P. R.)

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1.
  • 2021
  • swepub:Mat__t
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2.
  • 2021
  • swepub:Mat__t
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3.
  • Glasbey, JC, et al. (författare)
  • 2021
  • swepub:Mat__t
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4.
  • Tabiri, S, et al. (författare)
  • 2021
  • swepub:Mat__t
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5.
  • Bravo, L, et al. (författare)
  • 2021
  • swepub:Mat__t
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6.
  • 2017
  • Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:2
  • Tidskriftsartikel (refereegranskat)
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8.
  • Khatri, C, et al. (författare)
  • Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
  • 2021
  • Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
  • Tidskriftsartikel (refereegranskat)abstract
    • Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
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9.
  • Mishra, A., et al. (författare)
  • Stroke genetics informs drug discovery and risk prediction across ancestries
  • 2022
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 611, s. 115-123
  • Tidskriftsartikel (refereegranskat)abstract
    • Previous genome-wide association studies (GWASs) of stroke - the second leading cause of death worldwide - were conducted predominantly in populations of European ancestry(1,2). Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis(3), and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach(4), we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry(5). Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries.
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12.
  • Weinstock, Joshua S, et al. (författare)
  • Aberrant activation of TCL1A promotes stem cell expansion in clonal haematopoiesis.
  • 2023
  • Ingår i: Nature. - 1476-4687. ; 616:7958, s. 755-763
  • Tidskriftsartikel (refereegranskat)abstract
    • Mutations in a diverse set of driver genes increase the fitness of haematopoietic stem cells (HSCs), leading to clonal haematopoiesis1. These lesions are precursors for blood cancers2-6, but the basis of their fitness advantage remains largely unknown, partly owing to a paucity of large cohorts in which the clonal expansion rate has been assessed by longitudinal sampling. Here, to circumvent this limitation, we developed a method to infer the expansion rate from data from a single time point. We applied this method to 5,071 people with clonal haematopoiesis. A genome-wide association study revealed that a common inherited polymorphism in the TCL1A promoter was associated with a slower expansion rate in clonal haematopoiesis overall, but the effect varied by driver gene. Those carrying this protective allele exhibited markedly reduced growth rates or prevalence of clones with driver mutations in TET2, ASXL1, SF3B1 and SRSF2, butthis effect was not seen inclones withdriver mutations in DNMT3A. TCL1A was not expressed in normal or DNMT3A-mutated HSCs, but the introduction of mutations in TET2 or ASXL1 led to the expression of TCL1A protein and the expansion of HSCs in vitro. The protective allele restricted TCL1A expression and expansion of mutant HSCs, as did experimentalknockdown of TCL1A expression. Forced expression of TCL1A promoted the expansion of human HSCs in vitro and mouse HSCs in vivo. Our results indicate that the fitness advantage of several commonly mutated driver genes in clonal haematopoiesis may be mediated by TCL1A activation.
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14.
  • Kukkonen, J., et al. (författare)
  • Towards a Comprehensive Evaluation of the Environmental and Health Impacts of Shipping Emissions
  • 2022
  • Ingår i: Springer Proceedings in Complexity. - Cham : Springer International Publishing. - 2213-8684 .- 2213-8692. ; , s. 329-336
  • Konferensbidrag (refereegranskat)abstract
    • We present a new concept for marine research, applied in the EU-funded project EMERGE, “Evaluation, control and Mitigation of the EnviRonmental impacts of shippinG Emissions” (2020–2024; https://emerge-h2020.eu/ ). For the first time, both the various marine and atmospheric impacts of the shipping sector have been and will be comprehensively analyzed, using a concerted modelling and measurements framework. The experimental part of the project focuses on five European geographical case studies in different ecologically vulnerable regions, and a mobile onboard case study. The EMERGE consortium has also developed a harmonised and integrated modelling framework to assess the combined impacts of shipping emissions, both (i) on the marine ecosystems and (ii) the atmospheric environment. The first results include substantial refinements of a range of models to be applied, especially those for the STEAM and OpenDrift models. In particular, the STEAM (Ship Traffic Emission Assessment Model) model has been extended to allow for the effects of atmospheric and oceanographic factors on the fuel consumption and emissions of the ships. The OpenDrift model has been improved to take into account the partitioning, degradation, and volatilization of pollutants in water. The predicted emission and discharge values have been used as input for both regional scale atmospheric dispersion models, such as WRF-CMAQ (Weather Research and Forecasting—Community Multiscale Air Quality Model) and SILAM (System for Integrated modeLling of Atmospheric composition), and water quality and circulation models, such as OpenDrift (Open source model for the drifting of substances in the ocean) and Delft3D (oceanographic model). The case study regions are Eastern Mediterranean, Northern Adriatic Sea, the Lagoon of Aveiro, the Solent Strait and the Öresund Strait. We have also conducted a substantial part of the experimental campaigns scheduled in the project. The final assessment will include the benefits and costs of control and mitigation options affecting water quality, air pollution exposure, health impacts, climate forcing, and ecotoxicological effects and bioaccumulation of pollutants in marine biota.
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15.
  • Wedemeyer, S., et al. (författare)
  • Solar Science with the Atacama Large Millimeter/Submillimeter Array-A New View of Our Sun
  • 2016
  • Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 200:1-4, s. 1-73
  • Forskningsöversikt (refereegranskat)abstract
    • The Atacama Large Millimeter/submillimeter Array (ALMA) is a new powerful tool for observing the Sun at high spatial, temporal, and spectral resolution. These capabilities can address a broad range of fundamental scientific questions in solar physics. The radiation observed by ALMA originates mostly from the chromosphere-a complex and dynamic region between the photosphere and corona, which plays a crucial role in the transport of energy and matter and, ultimately, the heating of the outer layers of the solar atmosphere. Based on first solar test observations, strategies for regular solar campaigns are currently being developed. State-of-the-art numerical simulations of the solar atmosphere and modeling of instrumental effects can help constrain and optimize future observing modes for ALMA. Here we present a short technical description of ALMA and an overview of past efforts and future possibilities for solar observations at submillimeter and millimeter wavelengths. In addition, selected numerical simulations and observations at other wavelengths demonstrate ALMA's scientific potential for studying the Sun for a large range of science cases.
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16.
  • Wedemeyer, S., et al. (författare)
  • SSALMON - The Solar Simulations for the Atacama Large Millimeter Observatory Network
  • 2015
  • Ingår i: Advances in Space Research. - : Elsevier BV. - 1879-1948 .- 0273-1177. ; 56:12, s. 2679-2692
  • Tidskriftsartikel (refereegranskat)abstract
    • The Solar Simulations for the Atacama Large Millimeter Observatory Network (SSALMON) was initiated in 2014 in connection with two ALMA development studies. The Atacama Large Millimeter/submillimeter Array (ALMA) is a powerful new tool, which can also observe the Sun at high spatial, temporal, and spectral resolution. The international SSALMONetwork aims at co-ordinating the further development of solar observing modes for ALMA and at promoting scientific opportunities for solar physics with particular focus on numerical simulations, which can provide important constraints for the observing modes and can aid the interpretation of future observations. The radiation detected by ALMA originates mostly in the solar chromosphere - a complex and dynamic layer between the photosphere and corona, which plays an important role in the transport of energy and matter and the heating of the outer layers of the solar atmosphere. Potential targets include active regions, prominences, quiet Sun regions, flares. Here, we give a brief overview over the network and potential science cases for future solar observations with ALMA.
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17.
  • Bisht, D. S., et al. (författare)
  • Tethered balloon-born and ground-based measurements. of black carbon and particulate profiles within the lower troposphere during the foggy period in Delhi, India
  • 2016
  • Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 573, s. 894-905
  • Tidskriftsartikel (refereegranskat)abstract
    • The ground and vertical profiles of particulate matter (PM) were mapped as part of a pilot study using a Tethered balloon within the lower troposphere (1000 m) during the foggy episodes in the winter season of 2015-16 in New Delhi, India. Measurements of black carbon (BC) aerosol and PM <2.5 and 10 mu m (PM2.5 &PM-10 respectively) concentrations and their associated particulate optical properties along with meteorological parameters were made. The mean concentrations of PM2.5, PM10, BC370 (nm), and BC880 nm were observed to be 146.8 +/- 42.1, 245.4 +/- 65.4, 30.3 +/- 122, and 24.1 +/- 103 mu g m(-3), respectively. The mean value of PM2.5 was similar to 12 times higher than the annual US-EPA air quality standard. The fraction of BC in PM2.5 that contributed to absorption in the shorter visible wavelengths (BC370 nm) was-21%. Compared to clear days, the ground level mass concentrations of PM2.5 and BC370 nm particles were substantially increased (59% and 24%, respectively) during the foggy episode. The aerosol light extinction coefficient (sigma(ext)) value was much higher (mean: 610 Mm(-1)) during the lower visibility (foggy) condition. Higher concentrations of PM2.5 (89 mu g m(-3)) and longer visible wavelength absorbing BC880 am (25.7 mu g m(-3)) particles were observed up to 200 m. The BC880 nm and PM2.5 aerosol concentrations near boundary layer (1 km) were significantly higher (similar to 1.9 and 12 mu g m(-3)), respectively. The BC (i.e BCtot) aerosol direct radiative forcing (DRF) values were estimated at the top of the atmosphere (TOA), surface (SFC), and atmosphere (ATM) and its resultant forcing were- 75.5 Wm(-2) at SFC indicating the cooling effect at the surface. A positive value (20.9 Wm(-2)) of BC aerosol DRF at TOA indicated the warming effect at the top of the atmosphere over the study region. The net DRF value due to BC aerosol was positive (96.4 Wm(-2)) indicating a net warming effect in the atmosphere. The contribution of fossil and biomass fuels to the observed BC aerosol DRF values was -78% and-22%, respectively. The higher mean atmospheric heating rate (2.71 K clay(-1)) by BC aerosol in the winter season would probably strengthen the temperature inversion leading to poor dispersion and affecting the formation of clouds. Serious detrimental impacts on regional climate due to the high concentrations of BC and PM (especially PM2.5) aerosol are likely based on this study and suggest the need for immediate, stringent measures to improve the regional air quality in the northern India.
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18.
  • Forsberg, Lars A., et al. (författare)
  • Age-related somatic structural changes in the nuclear genome of human blood cells
  • 2012
  • Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 90:2, s. 217-228
  • Tidskriftsartikel (refereegranskat)abstract
    • Structural variations are among the most frequent interindividual genetic differences in the human genome. The frequency and distribution of de novo somatic structural variants in normal cells is, however, poorly explored. Using age-stratified cohorts of 318 monozygotic (MZ) twins and 296 single-born subjects, we describe age-related accumulation of copy-number variation in the nuclear genomes in vivo and frequency changes for both megabase- and kilobase-range variants. Megabase-range aberrations were found in 3.4% (9 of 264) of subjects ≥60 years old; these subjects included 78 MZ twin pairs and 108 single-born individuals. No such findings were observed in 81 MZ pairs or 180 single-born subjects who were ≤55 years old. Recurrent region- and gene-specific mutations, mostly deletions, were observed. Longitudinal analyses of 43 subjects whose data were collected 7-19 years apart suggest considerable variation in the rate of accumulation of clones carrying structural changes. Furthermore, the longitudinal analysis of individuals with structural aberrations suggests that there is a natural self-removal of aberrant cell clones from peripheral blood. In three healthy subjects, we detected somatic aberrations characteristic of patients with myelodysplastic syndrome. The recurrent rearrangements uncovered here are candidates for common age-related defects in human blood cells. We anticipate that extension of these results will allow determination of the genetic age of different somatic-cell lineages and estimation of possible individual differences between genetic and chronological age. Our work might also help to explain the cause of an age-related reduction in the number of cell clones in the blood; such a reduction is one of the hallmarks of immunosenescence.
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20.
  • Pinto, H., et al. (författare)
  • First-principles studies of the effect of (001) surface terminations on the electronic properties of the negatively charged nitrogen-vacancy defect in diamond
  • 2012
  • Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 86:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Density functional calculations have been carried out on (001)-orientated slabs of diamond with different surface terminations. A negatively charged nitrogen-vacancy defect (NV-) is placed in the middle of the slab approximately 1 nm from each surface and the effect of the surface on the internal optical transition in NV- investigated. The calculations show that the chemical nature of the surface is important. We find that although the clean surface does not lead to charge transfer between the defect and the surface, there is a splitting of the empty excited state, the final state in optical absorption, arising from a strong hybridization of the surface and defect bands. This leads to a broadening of the 1.945-eV transition of the NV- defect. OH- and F-terminated surfaces have no surface states in the band gap and again charge transfer between the defect and surface does not occur. The splitting of the e levels responsible for the optical transitions for OH or F termination is similar to that found in periodic boundary condition simulations for bulk diamond where the defects are separated by 1 nm, and thus the calculations show that hydroxylated or fluorinated surfaces give favorable optical properties.
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21.
  • Tiwari, Amit K., et al. (författare)
  • Calculated electron affinity and stability of halogen-terminated diamond
  • 2011
  • Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 84:24
  • Tidskriftsartikel (refereegranskat)abstract
    • The chemical termination of diamond has a dramatic impact on its electrical and chemical properties, where hydrogen and oxygen termination produce negative and positive electron affinities, respectively. However, the impact of halogen termination is not fully understood. We show that for low-index surfaces, 100% fluorinated surfaces exhibit chemically stable positive electron affinities in the 1.17 to 2.63 eV range, whereas 100% chlorination is energetically unfavorable. At lower coverage the positive electron affinity is smaller, being a combination of halogen-terminated and unterminated sites. For mixed halogen and hydrogen termination, a wide range of negative and positive electron affinities can be achieved by varying the relative concentrations of adsorbed species.
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22.
  • Tiwari, Amit K., et al. (författare)
  • Thermodynamic stability and electronic properties of F- and Cl-terminated diamond
  • 2012
  • Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley. - 1862-6300 .- 1862-6319. ; 209:9, s. 1709-1714
  • Tidskriftsartikel (refereegranskat)abstract
    • The chemical termination of diamond has important consequences for its electrical and chemical properties. Despite the impressive potential for various scientific and technological applications, halogen termination of diamond is not fully understood. We find using first principle atomistic simulation that 100% fluorinated diamond (100) surface exhibit a chemically stable positive electron affinity of 2.13 eV, whereas 100% chlorination is energetically unfavourable. The positive electron affinity of halogenated diamond generally increases with increasing surface coverage. For mixed halogen and hydrogen termination, a wide range of negative and positive electron affinities can be achieved theoretically by varying the relative concentrations of adsorbed species.
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24.
  • Nayak, S., et al. (författare)
  • Low-temperature anomalous magnetic behavior of Co2TiO4 and Co2SnO4
  • 2016
  • Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 120:16
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the low-temperature anomalous magnetic behavior of ferrimagnetic spinels cobalt orthotitanate (Co2TiO4), which exhibits magnetic compensation behavior across 31.74 K, and cobalt orthostannate (Co2SnO4) exhibiting two sequential magnetic transitions, namely (i) ferrimagnetic to paramagnetic transition with Neel temperature T-N similar to 41 K and reentrant spin-glass behavior with glass transition temperature T-SG similar to 39 K. The Arrott plot (H/M versus M-2) criterion has been used to extricate the order of sequential magnetic transitions occurring below TN. Negative slopes of the Arrott plots below 32 K, metamagnetic-like character of the M-H isotherms, anomalies in the specific-heat (C-P T-1 versus T) below 15 K, and a zero-crossover of isothermal magnetic-entropychange (Delta S) signify the presence of pseudo first-order discontinuous magnetic phase transition in the low-temperature regime 5K <= T <= 32 K. The dc- and ac-susceptibilities of both Co2TiO4 and Co2SnO4 are interpreted in terms of frozen-spin-clusters, which are responsible for very large magnitudes of the coercivity H-C similar to 20 kOe and bipolar-exchange bias H-EB similar to -20 kOe observed below 10 K.
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26.
  • Tiwari, Amit K., et al. (författare)
  • Bromine functionalisation of diamond : an ab initio study
  • 2012
  • Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley. - 1862-6300 .- 1862-6319. ; 209:9, s. 1703-1708
  • Tidskriftsartikel (refereegranskat)abstract
    • Immobilisation of organic molecules on diamond surfaces is of great interest for biomedical applications. While H, F and Cl terminations, as a linker, have been studied extensively, the bromination of diamond is not fully understood. We have performed ab initio simulations to investigate the chemisorption of Br onto C- and H-terminated diamond (100) surfaces. We find that due to steric interaction, 100% surface coverage of Br is not stable, however, surface coverage up to around 50% is theoretically achievable. The chemisorption energies corresponding to lower surface coverages of Br are found comparable to those of hydrogen. Partial surface coverages (25 and 50%) of Br on C-terminated diamond exhibit nearly equal positive electron affinities of 0.45 and 0.52 eV, respectively. Addition of hydrogen reduces the electron affinity and for 25% of Br on an otherwise H-terminated surface, a negative electron affinity of 0.57 eV is calculated.
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27.
  • Tiwari, Amit K., et al. (författare)
  • Effect of different surface coverages of transition metals on the electronic and structural properties of diamond
  • 2012
  • Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley. - 1862-6300 .- 1862-6319. ; 209:9, s. 1697-1702
  • Tidskriftsartikel (refereegranskat)abstract
    • The presence of adsorbate species on diamond surfaces, even in relatively small concentrations, strongly influences electrical, chemical and structural properties. Despite the technological significance, coverage of diamond by transition metals has received relatively little attention. In this paper, we present the results of density functional calculations examining up to a mono-layer of transition metals on the (001) diamond surface. We find that addition of carbide forming species, such as Ti, results in significantly higher adsorption energies at all surface coverages relative to non-carbide forming species. For monolayer coverage by Cu, and sub-monolayer coverage by Ti, we find a negative electron affinity. We propose that based upon the electron affinities and binding energies, metal-terminated (001) diamond surfaces are promising candidates for electron emission device applications.
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28.
  • Tiwari, Amit K., et al. (författare)
  • Electronic and structural properties of diamond (001) surfaces terminated by selected transition metals
  • 2012
  • Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 86:15
  • Tidskriftsartikel (refereegranskat)abstract
    • The presence of adsorbate species on diamond surfaces, even in small concentrations, strongly influences electrical, chemical, and structural properties. Despite the technological significance, coverage of diamond by transition metals has received relatively little attention. In this paper, we present the results of density functional calculations examining up to a monolayer of selected metals (Cu, Ni, Ti, and V) on the (001) diamond surface. We find that addition of carbide forming species (Ti and V) results in significantly higher adsorption energies at all surface coverages relative to those of the non-carbide-forming species. For monolayer coverage by Cu or Ni, and submonolayer coverage by Ti and V, we find large, negative electron affinities. We propose that based upon the electron affinities and binding energies, metal-terminated (001) diamond surfaces are promising candidates for electron emission device applications
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30.
  • Cole, J. W., et al. (författare)
  • The copy number variation and stroke (CaNVAS) risk and outcome study
  • 2021
  • Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:4 April
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose The role of copy number variation (CNV) variation in stroke susceptibility and outcome has yet to be explored. The Copy Number Variation and Stroke (CaNVAS) Risk and Outcome study addresses this knowledge gap. Methods Over 24,500 well-phenotyped IS cases, including IS subtypes, and over 43,500 controls have been identified, all with readily available genotyping on GWAS and exome arrays, with case measures of stroke outcome. To evaluate CNV-associated stroke risk and stroke outcome it is planned to: 1) perform Risk Discovery using several analytic approaches to identify CNVs that are associated with the risk of IS and its subtypes, across the age-, sex- and ethnicity-spectrums; 2) perform Risk Replication and Extension to determine whether the identified stroke-associated CNVs replicate in other ethnically diverse datasets and use biomarker data (e.g. methylation, proteomic, RNA, miRNA, etc.) to evaluate how the identified CNVs exert their effects on stroke risk, and lastly; 3) perform outcome-based Replication and Extension analyses of recent findings demonstrating an inverse relationship between CNV burden and stroke outcome at 3 months (mRS), and then determine the key CNV drivers responsible for these associations using existing biomarker data. Results The results of an initial CNV evaluation of 50 samples from each participating dataset are presented demonstrating that the existing GWAS and exome chip data are excellent for the planned CNV analyses. Further, some samples will require additional considerations for analysis, however such samples can readily be identified, as demonstrated by a sample demonstrating clonal mosaicism. Conclusion The CaNVAS study will cost-effectively leverage the numerous advantages of using existing case-control data sets, exploring the relationships between CNV and IS and its subtypes, and outcome at 3 months, in both men and women, in those of African and European-Caucasian descent, this, across the entire adult-age spectrum. Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
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31.
  • Malik, Yashpal Singh, et al. (författare)
  • Coronavirus Disease Pandemic (COVID-19) : Challenges and a Global Perspective
  • 2020
  • Ingår i: Pathogens. - : MDPI AG. - 2076-0817. ; 9:7
  • Forskningsöversikt (refereegranskat)abstract
    • The technology-driven world of the 21st century is currently confronted with a major threat to humankind, represented by the coronavirus disease (COVID-19) pandemic, caused by the severe acute respiratory syndrome, coronavirus-2 (SARS-CoV-2). As of now, COVID-19 has affected more than 6 million confirmed cases and took 0.39 million human lives. SARS-CoV-2 spreads much faster than its two ancestors, SARS-CoV and Middle East respiratory syndrome-CoV (MERS-CoV), but has low fatality rates. Our analyses speculate that the efficient replication and transmission of SARS-CoV-2 might be due to the high-density basic amino acid residues, preferably positioned in close proximity at both the furin-like cleavage sites (S1/S2 and S2 ') within the spike protein. Given the high genomic similarities of SARS-CoV-2 to bat SARS-like CoVs, it is likely that bats serve as a reservoir host for its progenitor. Women and children are less susceptible to SARS-CoV-2 infection, while the elderly and people with comorbidities are more prone to serious clinical outcomes, which may be associated with acute respiratory distress syndrome (ARDS) and cytokine storm. The cohesive approach amongst researchers across the globe has delivered high-end viral diagnostics. However, home-based point-of-care diagnostics are still under development, which may prove transformative in current COVID-19 pandemic containment. Similarly, vaccines and therapeutics against COVID-19 are currently in the pipeline for clinical trials. In this review, we discuss the noteworthy advancements, focusing on the etiological viral agent, comparative genomic analysis, population susceptibility, disease epidemiology and diagnosis, animal reservoirs, laboratory animal models, disease transmission, therapeutics, vaccine challenges, and disease mitigation measures.
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32.
  • Maziarz, RT, et al. (författare)
  • Patient-reported long-term quality of life after tisagenlecleucel in relapsed/refractory diffuse large B-cell lymphoma
  • 2020
  • Ingår i: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 4:4, s. 629-637
  • Tidskriftsartikel (refereegranskat)abstract
    • The JULIET phase 2 trial evaluated a single infusion of tisagenlecleucel in adult patients with relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL). The objective of the current analysis was to evaluate patient-reported health-related quality of life (HRQoL) with a median follow-up of 19.3 months among patients infused with a single dose of tisagenlecleucel. Patients enrolled were ≥18 years of age with r/r DLBCL after ≥2 lines of therapy and had either undergone a failed autologous stem cell transplant or were ineligible for the procedure. Two validated HRQoL instruments, Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) and Short Form-36 (SF-36) Health Survey, were used to measure HRQoL at baseline and months 3, 6, 12, and 18. At data cutoff (21 May 2018), 115 patients had received tisagenlecleucel infusion. Among the 99 patients evaluated, overall response rate was 54%, and 40% of patients achieved complete response (CR). Initially, 108 patients completed the HRQoL assessments at baseline, including 57 patients who eventually achieved CR or partial response (PR). Further, 30 and 21 patients in clinical response who completed assessments at baseline also completed assessments at months 12 and 18, respectively. Patients who achieved CR or PR sustained HRQoL improvement in all FACT scores at all time points. SF-36 instruments showed improvement above the minimal clinically important differences on 5 of 8 subscales. Long-term follow-up in the phase 2 JULIET study demonstrated that patients with r/r DLBCL who respond to tisagenlecleucel therapy had sustained, clinically meaningful improvements in HRQoL. This trial was registered at www.clinicaltrials.gov as #NCT02445248.
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33.
  • Norgate, Marc, et al. (författare)
  • On the heat waves over India and their future projections under different SSP scenarios from CMIP6 models
  • 2024
  • Ingår i: International Journal of Climatology. - 0899-8418 .- 1097-0088. ; 44:3, s. 973-995
  • Tidskriftsartikel (refereegranskat)abstract
    • Thirteen Coupled Model Intercomparison Project phase 6 (CMIP6) models were employed to simulate mean, maximum, and minimum temperature across 7 homogenous temperature regions of India for both annual and summer season (June, July, and August (JJA)). The model fidelity was assessed by comparing them with observed Climate Research Unit temperature dataset. The JJA multi-model ensemble for the present (1981–2014) suggests large warm biases in the temperature. Although the models could simulate the spatial variability of the mean and maximum temperature over most of the homogeneous regions, they do not compare well for representing the temporal variability. We also found, that although different individual models have strengths and weaknesses in representing spatial and temporal temperature characteristics over India, a few of the models perform better than the others. For example, CNRM-CM6 could better represent the spatial temperature patterns however they struggle in capturing the temporal variability. HadGEM3-GC31-LL, KACE-1-0G, and UKESM1-0-LL are comparably the best-performing models for temporal temperature features over India. The annual maximum temperature during far future period is projected to increase by 1.5°C, 2.3°C, and 4.1°C for Socioeconomic Pathways (SSPs) SSP1-2.6, SSP2-4.5, and SSP5-8.5 respectively. At regional scales, JJA mean temperature for SSP5-8.5 revealed significant increases in Interior Peninsula (3.8°C), Western Himalaya (5.6°C), Northwest (3.9°C), West Coast (3.6°C), East Coast (3.6°C), Northeast (3.6°C), and North Central (3.8°C), highlighting the Western Himalaya's heightened sensitivity. Further, heat wave frequency is projected to rise, with the northern territories (NW, NC, NE, and part of IP) most affected, anticipating week-long heat waves affecting around 50% of India's population under stronger SSPs. Such unprecedented impacts seem to be less profound in case of abatement scenarios such as the SSP1-2.6. Our findings support the urgent need for more ambitious mitigation and adaptation strategies to alleviate the public health impacts of climate change. 
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34.
  • Rai, Radheshyam, et al. (författare)
  • Experimental Techniques: An Introductory Overview
  • 2012
  • Ingår i: Synthesis, Characterization and Application of Smart Materials. - USA : Nova Science Publishers, Inc.. - 9781614706427 ; , s. 15-30
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Smart materials, one of the more focused points in materials research, deal primarily with the chemistry, physics and applications of materials in the real world because it induces conformational changes in complex structures and properties which are useful for the control of them. The thrust area of these types of materials are the combination of functional properties like thermal, electric, magnetic, superconducting and optical, which have led to the development of a wide range of new technological devices. These types of materials have been found to be very useful and interesting for various solid state devices. This book examines research developments of smart materials, including processing, properties and applications, which include device materials and environmentally friendly materials. (Imprint: Nova)
  •  
35.
  • Ray, A. K., et al. (författare)
  • Damage resistance of a thermal barrier coated superalloy used in aero turbine blade under accelerated creep condition
  • 2009
  • Ingår i: High Temperature Materials and Processes. - 0334-6455 .- 2191-0324. ; 28:1-2, s. 35-53
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper highlights the hot tensile and accelerated creep properties of a thermal barrier coated (TBC) AE 437A alloy used as a candidate blade material in aero engines. Acoustic emission technique has been utilised to characterise the ductile-brittle transition temperature of the bond coat. Results revealed that the DBTT (ductile to brittle transition temperature) of this bond coat is around 923 K, which is in close proximity to the value reported for NiCoCrAlY type of bond coat. Finite element technique used for analysing the equivalent stresses in the bond coat well within the elastic limit, revealed highest order of equivalent stress at 1073 K as the bond coat is ductile above 923 K. The lifetime of the TBC coated superai loy was superior to that of the bare substrate and that oxidation is likely the cause of the reduced life of the bare substrate as compared to the coated substrate while stress rupture or accelerated creep experiments are carried out in an oxidizing environment.. Delamination of the bond coat and that of the TBC at high stresses during accelerated creep was evident. During accelerated creep, the mode of fracture in the substrate at very high stresses was transgranular whereas that at low stresses was intergranular.
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36.
  • Tiwari, Ashutosh, et al. (författare)
  • Bionanomaterials for Emerging Biosensors Technology
  • 2012
  • Ingår i: Synthesis, Characterization and Application of Smart Materials. - USA : Nova Science Publishers, Inc.. - 9781614706427 ; , s. 137-154
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Smart materials, one of the more focused points in materials research, deal primarily with the chemistry, physics and applications of materials in the real world because it induces conformational changes in complex structures and properties which are useful for the control of them. The thrust area of these types of materials are the combination of functional properties like thermal, electric, magnetic, superconducting and optical, which have led to the development of a wide range of new technological devices. These types of materials have been found to be very useful and interesting for various solid state devices. This book examines research developments of smart materials, including processing, properties and applications, which include device materials and environmentally friendly materials
  •  
37.
  • Tiwari, Amit Kumar, et al. (författare)
  • Transition metal oxide-diamond interfaces for electron emission applications
  • 2013
  • Ingår i: Silicon carbide and related materials 2012. - Durnten-Zurich : Trans Tech Publications Inc.. - 9783037856246 ; , s. 761-764
  • Konferensbidrag (refereegranskat)abstract
    • Diamond surfaces with suitable adsorbed chemical species can exhibit both negative and positive electron affinities, arising from the complex electrostatic interplay between adsorbates and surface carbon atoms of diamond lattice. We present the results of density functional calculations into the energetics and the electron affinity of diamond (100) surfaces terminated with the oxides of selected transition metals. We find that for a correct stoichiometry, oxides of transition metals, such as Ti and Zn, exhibit a large negative electronic affinity of around 3 eV. The desorption of transition metal oxides is found to be highly endothermic. We therefore propose that transition metal oxides are promising for the surface coating of diamond-based electron emitters, as these exhibit higher thermal stability in comparison to the commonly used Cs-O termination, while retaining the advantage of inducing a large negative electron affinity
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38.
  • Tiwari, Amit K., et al. (författare)
  • Ultra thin transition metal oxide coatings on diamond for thermionic applications
  • 2013
  • Ingår i: Proceedings of the MRS Fall Meeting Symposim, MRS Fall Meeting, 24-29 November 2012, Boston, USA. - Warrendale : Materials Research Society. ; , s. 13-18
  • Konferensbidrag (refereegranskat)abstract
    • We have investigated, using density functional simulations, the energetics and the electronic properties of oxides of selected transition metals, TMs, adsorbed onto a diamond (001) surface. We find that stoichiometric oxides of TMs, particularly Ti and Zn, influence the electron affinity of diamond strongly. The electron affinities of stoichiometric oxides of Ti and Zn are calculated to be around -3eV, significantly higher than 1.9eV of commonly used H-termination. The reactions of TMs with an oxygenated diamond are found to be highly exothermic. Based upon the energetics and the electronic properties, we propose that in the regime of ultra thin films, oxides of TMs are promising options for surface coating of diamond-based electron emitters, as these coatings are compatible with semiconductor device fabrication processes, while having the benefit of inducing a large negative electron affinity
  •  
39.
  • Tiwari, Ashutosh, et al. (författare)
  • Vinyls Modified Guar Gum Biodegradable Plastics
  • 2012
  • Ingår i: Synthesis, Characterization and Application of Smart Materials. - USA : Nova Science Publishers, Inc.. - 9781614706427 ; , s. 125-136
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Smart materials, one of the more focused points in materials research, deal primarily with the chemistry, physics and applications of materials in the real world because it induces conformational changes in complex structures and properties which are useful for the control of them. The thrust area of these types of materials are the combination of functional properties like thermal, electric, magnetic, superconducting and optical, which have led to the development of a wide range of new technological devices. These types of materials have been found to be very useful and interesting for various solid state devices. This book examines research developments of smart materials, including processing, properties and applications, which include device materials and environmentally friendly materials
  •  
40.
  • Tiwari, A., et al. (författare)
  • Weibull triaxiality : A novel constraint assessment parameter for cleavage fracture in ductile to brittle transition region
  • 2018
  • Ingår i: Fatigue and Fracture of Engineering Materials and Structures. - : Wiley. - 8756-758X. ; 41:6, s. 1389-1401
  • Tidskriftsartikel (refereegranskat)abstract
    • The cleavage fracture probability of ferritic and ferritic/martensitic steels is generally computed using Beremin's model. In this work, a novel approach is developed for Beremin's model to be applicable to crack tip conditions under nonself similar stress field. The modification of Beremin's model corrects the inaccurate integration of local cleavage fracture probabilities of reference volume elements due to the incorrect assumption of self similar stress field under large-scale yielding. Under small-scale yielding condition, where stresses remain self similar, integration of local cleavage failure probability is accurate. However, when the stresses differ along the thickness due to constraint loss, the integration of local cleavage fracture probability is inaccurate due to the fact that the stress levels are not same in all the reference volume elements. The modification developed in this work in the form of a parameter named Weibull Triaxiality, which measures the deviation of a crack tip volume from one under self similar stress field.
  •  
41.
  • Tiwari, D., et al. (författare)
  • Influence of MgO barrier quality on spin-transfer torque in magnetic tunnel junctions
  • 2018
  • Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 112:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We studied the bias dependence of spin transfer torque in the MgO-based magnetic tunnel junction using a field-modulated spin torque ferromagnetic resonance measurement technique for three devices with tunneling magnetoresistances (MRs) of 60%, 67%, and 73%, respectively. The devices with a lower MR ratio showed the presence of multiple modes, while the device with higher MR (73%) showed a single resonance mode. We found a lower out-of-plane torkance in our devices compared to the in-plane torkance. The out-of-plane torque is linear with applied bias, while the bias dependence of in-plane torque shows a strong dependence on the MR ratio and hence the barrier quality. Published by AIP Publishing.
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42.
  • Tiwari, Suresh, et al. (författare)
  • Atmospheric heating due to black carbon aerosol during the summer monsoon period over Ballia : A rural environment over Indo-Gangetic Plain
  • 2016
  • Ingår i: Atmospheric research. - : Elsevier BV. - 0169-8095 .- 1873-2895. ; 178, s. 393-400
  • Tidskriftsartikel (refereegranskat)abstract
    • Black carbon (BC) aerosols are one of the most uncertain drivers of global climate change. The prevailing view is that BC mass concentrations are low in rural areas where industrialization and vehicular emissions are at a minimum. As part of a national research program called the Ganga Basin Ground Based Experiment-2014 under the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) Phase-III of Ministry of Earth Sciences, Government of India, the continuous measurements of BC and particulate matter (PM) mass concentrations, were conducted in a rural environment in the highly-polluted Indo-Gangetic Plain region during 16th June to 15th August (monsoon period), 2014. The mean mass concentration of BC was 4.03 (+/- 0.85) mu g m(-3) with a daily variability between 2.4 and 5.64 mu g m(-3), however, the mean mass PM concentrations [near ultrafine (PM1.0), fine (PM2.5) and inhalable (PM1.0)] were 29.1(+/- 16.2), 34.7 (+/- 19.9) and 43.7 (+/- 283) mu g m(-3), respectively. The contribution of BC in PM1.0 was approximately 13%, which is one of the highest being recorded. Diurnally, the BC mass concentrations were highest (mean: 5.89 mu g m(-3)) between 20:00 to 22:00 local time (LT) due to the burning of biofuels/biomass such as wood, dung, straw and crop residue mixed with dung by the local residents for cooking purposes. The atmospheric direct radiative forcing values due to the composite and BC aerosols were determined to be +78.3, +44.9, and +45.0 W m(-2) and +42.2, +35.4 and +34.3 W m(-2) during the months ofJune, July and August, respectively. The corresponding atmospheric heating rates (AHR) for composite and BC aerosols were 2.21,1.26 and 1.26; and 1.19, 0.99 and 0.96 K day(-1) for the month ofJune, July and August, respectively, with a mean of 1.57 and 1.05 K day(-1) which was 33% lower AHR (BC) than for the composite particles during the study period. This high AHR underscores the importance of absorbing aerosols such as BC contributed by residential cooking using biofuels in India. Our study demonstrates the need for immediate, effective regulations and policies that mitigate the emission of BC particles from domestic cooking in rural areas of India.
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43.
  • Tiwari, S., et al. (författare)
  • Design considerations and laboratory testing of power circuits for parallel operation of silicon carbide MOSFETs
  • 2015
  • Ingår i: 17th European Conference on Power Electronics and Applications, EPE-ECCE Europe 2015, Geneva, Switzerland, 8-10 September. - 9789075815221
  • Konferensbidrag (refereegranskat)abstract
    • In this paper, the impact of using parallel SiC MOSFETs as the switching device is investigated. Measurement considerations for a double pulse test are discussed, and the influence of the load inductor characteristic and the voltage measurement technique on the measurement results is demonstrated. It is shown that the inductor load can produce high frequency oscillations of up to 10 % of the load current in the switching current, which can wrongly be associated with the switching device. It is also shown that the standard earth connection of passive voltage probes can induce an extra stray inductance in the measurement loop, which can lead to a measurement of an extra overvoltage of up to 50 V, which is not due to the actual switching. Moreover, the dependency of turn-on and turn-off losses on the load current and the dc-link voltage is presented. It is shown that doubling the load current would increase the switching losses more than the double amount. Therefore, use of two parallel MOSFETs instead of a single one would decrease the total switching losses for a given load current. On the other hand, the parallel configuration is shown to have a higher overvoltage than one single MOSFET for a similar load current. This, however, can be reduced by a higher gate resistance which will eventually keep the total switching loss of parallel configuration equal to the single MOSFET configuration for a given load current. Finally, it is also shown that switching losses can be greatly decreased by decreasing the gate resistance, but this leads to a higher overvoltage on the device. Therefore, the final choice for design is a compromise between the switching losses and the overvoltage.
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