| 1. |
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| 2. |
- Namkoong, H, et al.
(författare)
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DOCK2 is involved in the host genetics and biology of severe COVID-19
- 2022
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 609:7928, s. 754-
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Tidskriftsartikel (refereegranskat)abstract
- Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge1–5. Here we conducted a genome-wide association study (GWAS) involving 2,393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3,289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target.
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| 3. |
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| 4. |
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| 5. |
- Kanis, J A, et al.
(författare)
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Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX.
- 2023
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Ingår i: Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. - : Springer Nature. - 1433-2965 .- 0937-941X. ; 34:12, s. 2027-2045
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Tidskriftsartikel (refereegranskat)abstract
- A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients.A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination.A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.
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| 6. |
- Vandenput, L., et al.
(författare)
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A meta-analysis of previous falls and subsequent fracture risk in cohort studies
- 2024
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Ingår i: Osteoporosis International. - : Springer Nature. - 0937-941X .- 1433-2965. ; 35:3, s. 469-494
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Tidskriftsartikel (refereegranskat)abstract
- Summary: The relationship between self-reported falls and fracture risk was estimated in an international meta-analysis of individual-level data from 46 prospective cohorts. Previous falls were associated with an increased fracture risk in women and men and should be considered as an additional risk factor in the FRAX® algorithm. Introduction: Previous falls are a well-documented risk factor for subsequent fracture but have not yet been incorporated into the FRAX algorithm. The aim of this study was to evaluate, in an international meta-analysis, the association between previous falls and subsequent fracture risk and its relation to sex, age, duration of follow-up, and bone mineral density (BMD). Methods: The resource comprised 906,359 women and men (66.9% female) from 46 prospective cohorts. Previous falls were uniformly defined as any fall occurring during the previous year in 43 cohorts; the remaining three cohorts had a different question construct. The association between previous falls and fracture risk (any clinical fracture, osteoporotic fracture, major osteoporotic fracture, and hip fracture) was examined using an extension of the Poisson regression model in each cohort and each sex, followed by random-effects meta-analyses of the weighted beta coefficients. Results: Falls in the past year were reported in 21.4% of individuals. During a follow-up of 9,102,207 person-years, 87,352 fractures occurred of which 19,509 were hip fractures. A previous fall was associated with a significantly increased risk of any clinical fracture both in women (hazard ratio (HR) 1.42, 95% confidence interval (CI) 1.33–1.51) and men (HR 1.53, 95% CI 1.41–1.67). The HRs were of similar magnitude for osteoporotic, major osteoporotic fracture, and hip fracture. Sex significantly modified the association between previous fall and fracture risk, with predictive values being higher in men than in women (e.g., for major osteoporotic fracture, HR 1.53 (95% CI 1.27–1.84) in men vs. HR 1.32 (95% CI 1.20–1.45) in women, P for interaction = 0.013). The HRs associated with previous falls decreased with age in women and with duration of follow-up in men and women for most fracture outcomes. There was no evidence of an interaction between falls and BMD for fracture risk. Subsequent risk for a major osteoporotic fracture increased with each additional previous fall in women and men. Conclusions: A previous self-reported fall confers an increased risk of fracture that is largely independent of BMD. Previous falls should be considered as an additional risk factor in future iterations of FRAX to improve fracture risk prediction.
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| 7. |
- Vandenput, Liesbeth, 1974, et al.
(författare)
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Update of the fracture risk prediction tool FRAX : a systematic review of potential cohorts and analysis plan
- 2022
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Ingår i: Osteoporosis International. - : Springer. - 0937-941X .- 1433-2965. ; 33:10, s. 2103-2136
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Forskningsöversikt (refereegranskat)abstract
- Summary: We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.Introduction: The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors.Methods: A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible.Results: Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed.Conclusions: These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).
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| 8. |
- Martin, S., et al.
(författare)
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ALCHEMI, an ALMA Comprehensive High-resolution Extragalactic Molecular Inventory: Survey presentation and first results from the ACA array
- 2021
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 656
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Tidskriftsartikel (refereegranskat)abstract
- Context. The interstellar medium is the locus of physical processes affecting the evolution of galaxies which drive or are the result of star formation activity, supermassive black hole growth, and feedback. The resulting physical conditions determine the observable chemical abundances that can be explored through molecular emission observations at millimeter and submillimeter wavelengths. Aims. Our goal is to unveiling the molecular richness of the central region of the prototypical nearby starburst galaxy NGC 253 at an unprecedented combination of sensitivity, spatial resolution, and frequency coverage. Methods. We used the Atacama Large Millimeter/submillimeter Array (ALMA), covering a nearly contiguous 289 GHz frequency range between 84.2 and 373.2 GHz, to image the continuum and spectral line emission at 1.6″(∼28 pc) resolution down to a sensitivity of 30 - 50 mK. This article describes the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory (ALCHEMI) large program. We focus on the analysis of the spectra extracted from the 15″ (∼255 pc) resolution ALMA Compact Array data. Results. We modeled the molecular emission assuming local thermodynamic equilibrium with 78 species being detected. Additionally, multiple hydrogen and helium recombination lines are identified. Spectral lines contribute 5 to 36% of the total emission in frequency bins of 50 GHz. We report the first extragalactic detections of C2H5OH, HOCN, HC3HO, and several rare isotopologues. Isotopic ratios of carbon, oxygen, sulfur, nitrogen, and silicon were measured with multiple species. Concluison. Infrared pumped vibrationaly excited HCN, HNC, and HC3N emission, originating in massive star formation locations, is clearly detected at low resolution, while we do not detect it for HCO+. We suggest high temperature conditions in these regions driving a seemingly "carbon-rich"chemistry which may also explain the observed high abundance of organic species close to those in Galactic hot cores. The Lvib/LIR ratio was used as a proxy to estimate a 3% contribution from the proto super star cluster to the global infrared emission. Measured isotopic ratios with high dipole moment species agree with those within the central kiloparsec of the Galaxy, while those derived from 13C/18O are a factor of five larger, confirming the existence of multiple interstellar medium components within NGC 253 with different degrees of nucleosynthesis enrichment. The ALCHEMI data set provides a unique template for studies of star-forming galaxies in the early Universe.
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| 9. |
- Holdship, Jonathan, et al.
(författare)
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The distribution and origin of C 2 H in NGC 253 from ALCHEMI
- 2021
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 654
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Tidskriftsartikel (refereegranskat)abstract
- Context. Observations of chemical species can provide insights into the physical conditions of the emitting gas however it is important to understand how their abundances and excitation vary within different heating environments. C2H is a molecule typically found in PDR regions of our own Galaxy but there is evidence to suggest it also traces other regions undergoing energetic processing in extragalactic environments. Aims. As part of the ALCHEMI ALMA large program, we map the emission of C2H in the central molecular zone of the nearby starburst galaxy NGC 253 at 1.6″ (28 pc) resolution and characterize it to understand its chemical origins. Methods. We used spectral modeling of the N = 1-0 through N = 4-3 rotational transitions of C2H to derive the C2H column densities towards the dense clouds in NGC 253. We then use chemical modeling, including photodissociation region (PDR), dense cloud, and shock models to investigate the chemical processes and physical conditions that are producing the molecular emission. Results. We find high C2H column densities of ∼1015 cm-2 detected towards the dense regions of NGC 253. We further find that these column densities cannot be reproduced if it is assumed that the emission arises from the PDR regions at the edge of the clouds. Instead, we find that the C2H abundance remains high even in the high visual extinction interior of these clouds and that this is most likely caused by a high cosmic-ray ionization rate.
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| 10. |
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| 11. |
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| 12. |
- Chotiyarnwong, P., et al.
(författare)
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Is it time to consider population screening for fracture risk in postmenopausal women? A position paper from the International Osteoporosis Foundation Epidemiology/Quality of Life Working Group
- 2022
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Ingår i: Archives of Osteoporosis. - : Springer Science and Business Media LLC. - 1862-3522 .- 1862-3514. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- A Summary The IOF Epidemiology and Quality of Life Working Group has reviewed the potential role of population screening for high hip fracture risk against well-established criteria. The report concludes that such an approach should strongly be considered in many health care systems to reduce the burden of hip fractures. Introduction The burden of long-term osteoporosis management falls on primary care in most healthcare systems. However, a wide and stable treatment gap exists in many such settings; most of which appears to be secondary to a lack of awareness of fracture risk. Screening is a public health measure for the purpose of identifying individuals who are likely to benefit from further investigations and/or treatment to reduce the risk of a disease or its complications. The purpose of this report was to review the evidence for a potential screening programme to identify postmenopausal women at increased risk of hip fracture. Methods The approach took well-established criteria for the development of a screening program, adapted by the UK National Screening Committee, and sought the opinion of 20 members of the International Osteoporosis Foundation's Working Group on Epidemiology and Quality of Life as to whether each criterion was met (yes, partial or no). For each criterion, the evidence base was then reviewed and summarized. Results and Conclusion The report concludes that evidence supports the proposal that screening for high fracture risk in primary care should strongly be considered for incorporation into many health care systems to reduce the burden of fractures, particularly hip fractures. The key remaining hurdles to overcome are engagement with primary care healthcare professionals, and the implementation of systems that facilitate and maintain the screening program.
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| 13. |
- Harada, N., et al.
(författare)
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The ALCHEMI Atlas: Principal Component Analysis Reveals Starburst Evolution in NGC 253
- 2024
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Ingår i: Astrophysical Journal, Supplement Series. - 1538-4365 .- 0067-0049. ; 271:2
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Tidskriftsartikel (refereegranskat)abstract
- Molecular lines are powerful diagnostics of the physical and chemical properties of the interstellar medium (ISM). These ISM properties, which affect future star formation, are expected to differ in starburst galaxies from those of more quiescent galaxies. We investigate the ISM properties in the central molecular zone of the nearby starburst galaxy NGC 253 using the ultrawide millimeter spectral scan survey from the Atacama Large Millimeter/submillimeter Array Large Program ALCHEMI. We present an atlas of velocity-integrated images at a 1.″6 resolution of 148 unblended transitions from 44 species, including the first extragalactic detection of HCNH+ and the first interferometric images of C3H+, NO, and HCS+. We conduct a principal component analysis (PCA) on these images to extract correlated chemical species and to identify key groups of diagnostic transitions. To the best of our knowledge, our data set is currently the largest astronomical set of molecular lines to which PCA has been applied. The PCA can categorize transitions coming from different physical components in NGC 253 such as (i) young starburst tracers characterized by high-excitation transitions of HC3N and complex organic molecules versus tracers of on-going star formation (radio recombination lines) and high-excitation transitions of CCH and CN tracing photodissociation regions, (ii) tracers of cloud-collision-induced shocks (low-excitation transitions of CH3OH, HNCO, HOCO+, and OCS) versus shocks from star formation-induced outflows (high-excitation transitions of SiO), as well as (iii) outflows showing emission from HOC+, CCH, H3O+, CO isotopologues, HCN, HCO+, CS, and CN. Our findings show these intensities vary with galactic dynamics, star formation activities, and stellar feedback.
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| 14. |
- Huang, K. Y., et al.
(författare)
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Reconstructing the shock history in the CMZ of NGC 253 with ALCHEMI
- 2023
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Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 675
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Tidskriftsartikel (refereegranskat)abstract
- Context. HNCO and SiO are well-known shock tracers and have been observed in nearby galaxies, including the nearby (D = 3.5 Mpc) starburst galaxy NGC 253. The simultaneous detection of these two species in regions where the star-formation rate is high may be used to study the shock history of the gas. Aims. We perform a multi-line molecular study of NGC 253 using the shock tracers SiO and HNCO and aim to characterize its gas properties. We also explore the possibility of reconstructing the shock history in the central molecular zone (CMZ) of the galaxy. Methods. Six SiO transitions and eleven HNCO transitions were imaged at high resolution 1.·6 (28 pc) with the Atacama Large Millimeter/submillimeter Array (ALMA) as part of the ALCHEMI Large Programme. Both non local thermaldynamic equilibrium (non-LTE) radiative transfer analysis and chemical modeling were performed in order to characterize the gas properties and investigate the chemical origin of the emission. Results. The nonLTE radiative transfer analysis coupled with Bayesian inference shows clear evidence that the gas traced by SiO has different densities and temperatures than that traced by HNCO, with an indication that shocks are needed to produce both species. Chemical modeling further confirms such a scenario and suggests that fast and slow shocks are responsible for SiO and HNCO production, respectively, in most GMCs. We are also able to infer the physical characteristics of the shocks traced by SiO and HNCO for each GMC. Conclusions. Radiative transfer and chemical analysis of the SiO and HNCO in the CMZ of NGC 253 reveal a complex picture whereby most of the GMCs are subjected to shocks. We speculate on the possible shock scenarios responsible for the observed emission and provide potential history and timescales for each shock scenario. Observations of higher spatial resolution for these two species are required in order to quantitatively differentiate between the possible scenarios.
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| 15. |
- Humire, Pedro, et al.
(författare)
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Methanol masers in NGC 253 with ALCHEMI
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 663
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Tidskriftsartikel (refereegranskat)abstract
- Context. Methanol masers of Class I (collisionally pumped) and Class II (radiatively pumped) have been studied in great detail in our Galaxy in a variety of astrophysical environments such as shocks and star-forming regions and are they are helpful to analyze the properties of the dense interstellar medium. However, the study of methanol masers in external galaxies is still in its infancy. Aims. Our main goal is to search for methanol masers in the central molecular zone (CMZ; inner 500 pc) of the nearby starburst galaxy NGC253. Methods. Covering a frequency range between 84 and 373 GHz (λ = 3.6-0.8 mm) at high angular (1."6 ∼ 27 pc) and spectral (∼8-9 km s-1) resolution with ALCHEMI (ALMA Comprehensive High-resolution Extragalactic Molecular Inventory), we have probed dierent regions across the CMZ of NGC253. In order to look for methanol maser candidates, we employed the rotation diagram method and a set of radiative transfer models. Results.We detect for the first time masers above 84 GHz in NGC253, covering an ample portion of the J-1 (J-1)0-E line series (at 84, 132, 229, and 278 GHz) and the J0 (J-1)1 A series (at 95, 146, and 198 GHz). This confirms the presence of the Class I maser line at 84 GHz, which was already reported, but now being detected in more than one location. For the J-1 (J-1)0-E line series, we observe a lack of Class I maser candidates in the central star-forming disk. Conclusions. The physical conditions for maser excitation in the J-1 (J-1)0-E line series can be weak shocks and cloud-cloud collisions as suggested by shock tracers (SiO and HNCO) in bi-symmetric shock regions located in the outskirts of the CMZ. On the other hand, the presence of photodissociation regions due to a high star-formation rate would be needed to explain the lack of Class I masers in the very central regions.
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| 16. |
- Kerkhof, H. J. M., et al.
(författare)
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Recommendations for standardization and phenotype definitions in genetic studies of osteoarthritis: the TREAT-OA consortium
- 2011
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Ingår i: Osteoarthritis and Cartilage. - : Elsevier BV. - 1063-4584. ; 19:3, s. 254-264
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To address the need for standardization of osteoarthritis (OA) phenotypes by examining the effect of heterogeneity among symptomatic (SOA) and radiographic osteoarthritis (ROA) phenotypes. Methods: Descriptions of OA phenotypes of the 28 studies involved in the TREAT-OA consortium were collected. We investigated whether different OA definitions result in different association results by creating various hip OA definitions in one large population based cohort (the Rotterdam Study I (RSI)) and testing those for association with gender, age and body mass index using one-way ANOVA. For ROA, we standardized the hip-, knee- and hand ROA definitions and calculated prevalence's of ROA before and after standardization in nine cohort studies. This procedure could only be performed in cohort studies and standardization of SOA definitions was not feasible at this moment. Results: In this consortium, all studies with SOA phenotypes (knee, hip and hand) used a different definition and/or assessment of OA status. For knee-, hip- and hand ROA five, four and seven different definitions were used, respectively. Different hip ROA definitions do lead to different association results. For example, we showed in the RSI that hip OA defined as "at least definite joint space narrowing (JSN) and one definite osteophyte" was not associated with gender (P=0.22), but defined as "at least one definite osteophyte" was significantly associated with gender (P=3 x 10(-9)). Therefore, a standardization process was undertaken for ROA definitions. Before standardization a wide range of ROA prevalence's was observed in the nine cohorts studied. After standardization the range in prevalence of knee- and hip ROA was small. Conclusion: Phenotype definitions influence the prevalence of OA and association with clinical variables. ROA phenotypes within the TREAT-OA consortium were standardized to reduce heterogeneity and improve power in future genetics studies. (C) 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
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| 17. |
- Leyland, K. M., et al.
(författare)
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Harmonising measures of knee and hip osteoarthritis in population-based cohort studies : an international study
- 2018
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Ingår i: Osteoarthritis and Cartilage. - : Elsevier BV. - 1063-4584. ; 26:7, s. 872-879
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Population-based osteoarthritis (OA) cohorts provide vital data on risk factors and outcomes of OA, however the methods to define OA vary between cohorts. We aimed to provide recommendations for combining knee and hip OA data in extant and future population cohort studies, in order to facilitate informative individual participant level analyses. Method: International OA experts met to make recommendations on: 1) defining OA by X-ray and/or pain; 2) compare The National Health and Nutrition Examination Survey (NHANES)-type OA pain questions; 3) the comparability of the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) scale to NHANES-type OA pain questions; 4) the best radiographic scoring method; 5) the usefulness of other OA outcome measures. Key issues were explored using new analyses in two population-based OA cohorts (Multicenter Osteoarthritis Study; MOST and Osteoarthritis Initiative OAI). Results: OA should be defined by both symptoms and radiographs, with symptoms alone as a secondary definition. Kellgren and Lawrence (K/L) grade ≥2 should be used to define radiographic OA (ROA). The variable wording of pain questions can result in varying prevalence between 41.0% and 75.4%, however questions where the time anchor is similar have high sensitivity and specificity (91.2% and 89.9% respectively). A threshold of 3 on a 0–20 scale (95% CI 2.1, 3.9) in the WOMAC pain subscale demonstrated equivalence with the preferred NHANES-type question. Conclusion: This research provides recommendations, based on expert agreement, for harmonising and combining OA data in existing and future population-based cohorts.
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| 18. |
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| 19. |
- Pierot, L, et al.
(författare)
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Standards of Practice in Acute Ischemic Stroke Intervention International Recommendations
- 2019
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Ingår i: The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques. - : Cambridge University Press (CUP). - 0317-1671 .- 2057-0155. ; 46:3, s. 269-274
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Tidskriftsartikel (refereegranskat)abstract
- After five positive randomized controlled trials showed benefit of mechanical thrombectomy in the management of acute ischemic stroke with emergent large-vessel occlusion, a multi-society meeting was organized during the 17th Congress of the World Federation of Interventional and Therapeutic Neuroradiology in October 2017 in Budapest, Hungary. This multi-society meeting was dedicated to establish standards of practice in acute ischemic stroke intervention aiming for a consensus on the minimum requirements for centers providing such treatment. In an ideal situation, all patients would be treated at a center offering a full spectrum of neuroendovascular care (a level 1 center). However, for geographical reasons, some patients are unable to reach such a center in a reasonable period of time. With this in mind, the group paid special attention to define recommendations on the prerequisites of organizing stroke centers providing medical thrombectomy for acute ischemic stroke, but not for other neurovascular diseases (level 2 centers). Finally, some centers will have a stroke unit and offer intravenous thrombolysis, but not any endovascular stroke therapy (level 3 centers). Together, these level 1, 2, and 3 centers form a complete stroke system of care. The multi-society group provides recommendations and a framework for the development of medical thrombectomy services worldwide.
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| 20. |
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| 21. |
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| 22. |
- Tanaka, Kunihiko, et al.
(författare)
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Volume Density Structure of the Central Molecular Zone NGC 253 through ALCHEMI Excitation Analysis
- 2024
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Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 961:1
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Tidskriftsartikel (refereegranskat)abstract
- We present a spatially resolved excitation analysis for the central molecular zone (CMZ) of the starburst galaxy NGC 253 using the data from the Atacama Large Millimeter/submillimeter Array Comprehensive High-resolution Extragalactic Molecular Inventory, whereby we explore parameters distinguishing NGC 253 from the quiescent Milky Way’s Galactic center (GC). Non-LTE analyses employing a hierarchical Bayesian framework are applied to Band 3-7 transitions from nine molecular species to delineate the position-position-velocity distributions of column density ( N H 2 ), volume density ( n H 2 ), and temperature (T kin) at 27 pc resolution. Two distinct components are detected: a low-density component with ( n H 2 , T kin ) ∼ ( 10 3.3 cm − 3 , 85 K ) and a high-density component with ( n H 2 , T kin ) ∼ ( 10 4.4 cm − 3 , 110 K ) , separated at n H 2 ∼ 10 3.8 cm − 3 . NGC 253 has ∼10 times the high-density gas mass and ∼3 times the dense-gas mass fraction of the GC. These properties are consistent with their HCN/CO ratio but cannot alone explain the factor of ∼30 difference in their star formation efficiencies (SFEs), contradicting the dense-gas mass to star formation rate scaling law. The n H 2 histogram toward NGC 253 exhibits a shallow declining slope up to n H 2 ∼ 10 6 cm − 3 , while that of the GC steeply drops in n H 2 ≳ 10 4.5 cm − 3 and vanishes at 105 cm−3. Their dense-gas mass fraction ratio becomes consistent with their SFEs when the threshold n H 2 for the dense gas is taken at ∼104.2−4.6 cm−3. The rich abundance of gas above this density range in the NGC 253 CMZ, or its scarcity in the GC, is likely to be the critical difference characterizing the contrasting star formation in the centers of the two galaxies.
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| 23. |
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| 24. |
- Tiegs, Scott D., et al.
(författare)
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Global patterns and drivers of ecosystem functioning in rivers and riparian zones
- 2019
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Ingår i: Science Advances. - Washington : American Association of Advancement in Science. - 2375-2548. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.
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| 25. |
- Bao, Min, et al.
(författare)
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Physical properties of the southwest outflow streamer in the starburst galaxy NGC 253 with ALCHEMI
- 2024
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Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 687
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Tidskriftsartikel (refereegranskat)abstract
- Aims . The physical properties of galactic molecular outflows are important as they could constrain outflow formation mechanisms. In this work, we study the properties of the southwest (SW) outflow streamer including gas kinematics, optical depth, dense gas fraction, and shock strength through molecular emission in the central molecular zone of the starburst galaxy NGC 253. Methods . We imaged the molecular emission in NGC 253 at a spatial resolution of 1.600(∼27 pc at D ∼ 3.5 Mpc) based on data from the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory (ALCHEMI) large program. We traced the velocity and velocity dispersion of molecular gas with the CO(1–0) line and studied the molecular spectra in the region of the SW streamer, the brightest CO streamer in NGC 253. We constrained the optical depth of the CO emission with the CO/13CO(1–0) ratio, the dense gas fraction with the HCN/CO(1–0), H13CN/13CO(1–0) and N2H+/13CO(1–0) ratios, as well as the shock strength with the SiO(2–1)/13CO(1–0) and CH3OH(2k–1k)/13CO(1–0) ratios. Results . The CO/13CO(1–0) integrated intensity ratio is ∼21 in the SW streamer region, which approximates the C/13C isotopic abundance ratio. The higher integrated intensity ratio compared to the disk can be attributed to the optically thinner environment of CO(1–0) emission inside the SW streamer. The HCN/CO(1–0) and SiO(2–1)/13CO(1–0) integrated intensity ratios both approach ∼0.2 in three giant molecular clouds (GMCs) at the base of the outflow streamers, which implies a higher dense gas fraction and strength of fast shocks in those GMCs than in the disk, while the HCN/CO(1–0) integrated intensity ratio is moderate in the SW streamer region. The contours of those two integrated intensity ratios are extended in the directions of outflow streamers, which connect the enhanced dense gas fraction and shock strength with molecular outflow. Moreover, the molecular gas with an enhanced dense gas fraction and shock strength located at the base of the SW streamer shares the same velocity as the outflow. Conclusions . The enhanced dense gas fraction and shock strength at the base of the outflow streamers suggest that star formation inside the GMCs can trigger shocks and further drive the molecular outflow. The increased CO/13CO(1–0) integrated intensity ratio coupled with the moderate HCN/CO(1–0) integrated intensity ratio in the SW streamer region are consistent with the picture that the gas velocity gradient inside the streamer may decrease the optical depth of CO(1–0) emission, as well as the dense gas fraction in the extended streamer region.
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| 26. |
- Barrientos, Alejandro, et al.
(författare)
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Towards the prediction of molecular parameters from astronomical emission lines using Neural Networks
- 2021
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Ingår i: Experimental Astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 52:1-2, s. 157-182
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Tidskriftsartikel (refereegranskat)abstract
- Molecular astronomy is a field that is blooming in the era of large observatories such as the Atacama Large Millimeter/Submillimeter Array (ALMA). With modern, sensitive, and high spectral resolution radio telescopes like ALMA and the Square Kilometer Array, the size of the data cubes is rapidly escalating, generating a need for powerful automatic analysis tools. This work introduces MolPred, a pilot study to perform predictions of molecular parameters such as excitation temperature (Tex) and column density (log(N)) from input spectra by the use of neural networks. We used as test cases the spectra of CO, HCO+, SiO and CH3CN between 80 and 400 GHz. Training spectra were generated with MADCUBA, a state-of-the-art spectral analysis tool. Our algorithm was designed to allow the generation of predictions for multiple molecules in parallel. Using neural networks, we can predict the column density and excitation temperature of these molecules with a mean absolute error of 8.5% for CO, 4.1% for HCO+, 1.5% for SiO and 1.6% for CH3CN. The prediction accuracy depends on the noise level, line saturation, and number of transitions. We performed predictions upon real ALMA data. The values predicted by our neural network for this real data differ by 13% from the MADCUBA values on average. Current limitations of our tool include not considering linewidth, source size, multiple velocity components, and line blending.
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| 27. |
- Behrens, E., et al.
(författare)
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Tracing Interstellar Heating: An ALCHEMI Measurement of the HCN Isomers in NGC 253
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 939:2
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Tidskriftsartikel (refereegranskat)abstract
- We analyze HCN and HNC emission in the nearby starburst galaxy NGC 253 to investigate its effectiveness in tracing heating processes associated with star formation. This study uses multiple HCN and HNC rotational transitions observed using the Atacama Large Millimeter/submillimeter Array via the ALCHEMI Large Program. To understand the conditions and associated heating mechanisms within NGC 253's dense gas, we employ Bayesian nested sampling techniques applied to chemical and radiative transfer models, which are constrained using our HCN and HNC measurements. We find that the volume density n H 2 and cosmic-ray ionization rate (CRIR) ζ are enhanced by about an order of magnitude in the galaxy’s central regions as compared to those further from the nucleus. In NGC 253's central giant molecular clouds (GMCs), where observed HCN/HNC abundance ratios are the lowest, n ∼ 105.5 cm−3 and ζ ∼ 10−12 s−1 (greater than 104 times the average Galactic rate). We find a positive correlation in the association of both density and CRIR with the number of star formation-related heating sources (supernova remnants, H ii regions, and super hot cores) located in each GMC, as well as a correlation between CRIRs and supernova rates. Additionally, we see an anticorrelation between the HCN/HNC ratio and CRIR, indicating that this ratio will be lower in regions where ζ is higher. Though previous studies suggested HCN and HNC may reveal strong mechanical heating processes in NGC 253's CMZ, we find cosmic-ray heating dominates the heating budget, and mechanical heating does not play a significant role in the HCN and HNC chemistry.
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| 28. |
- Butterworth, Joshua, et al.
(författare)
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Molecular isotopologue measurements toward super star clusters and the relation to their ages in NGC 253 with ALCHEMI
- 2024
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Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 686
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Tidskriftsartikel (refereegranskat)abstract
- Context. Determining the evolution of the CNO isotopes in the interstellar medium (ISM) of starburst galaxies can yield important constraints on the ages of super star clusters (SSCs), or on other aspects and factors contributing to their evolution, such as the initial mass function (IMF). Due to the time-dependent nature of the abundances of isotopes within the ISM -as they are supplied from processes such as nucleosynthesis or chemical fractionation -, this provides the opportunity to test whether or not isotope ratios trace the ages of highly star-forming regions, such as SSCs. Aims. The goal of this study is to investigate whether the isotopic variations in SSC regions within NGC 253 are correlated with their different ages as derived from stellar population modelling. Methods. We measured abundance ratios of CO, HCN, and HCO+ isotopologues in six regions containing SSCs within NGC 253 using high-spatial-resolution (1.6″, ~28 pc) data from the ALCHEMI (ALma Comprehensive High-resolution Extragalactic Molecular Inventory) ALMA Large program. We then analysed these ratios using RADEX radiative transfer modelling, with the parameter space sampled using the nested sampling Monte Carlo algorithm MLFriends. These abundance ratios were then compared to ages predicted in each region via the fitting of observed star-formation tracers (such as Brγ) to Starburst99 starburst stellar population evolution models. Results. We determined the isotopic column density ratios across multiple regions of SSC activity in NGC 253 using non-LTE radiative transfer modelling. We do not find any significant trend with age for the CO and HCN isotopologue ratios on timescales of the ages of the SSC∗ regions observed. However, HCO+ may show a correlation with age over these timescales in 12C/13C. Conclusions. The driving factors of these ratios within SSCs could be the IMF or fractionation effects. To further probe these effects in SSCs over time, a larger sample of SSCs must be observed spanning a larger age range.
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| 29. |
- Haasler, D., et al.
(författare)
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First extragalactic detection of a phosphorus-bearing molecule with ALCHEMI: Phosphorus nitride (PN)
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 659
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Tidskriftsartikel (refereegranskat)abstract
- Context. Phosphorus (P) is a crucial element for life given its central role in several biomolecules. P-bearing molecules have been discovered in different regions of the Milky Way, but not yet towards an extragalactic environment. Aims. We searched for P-bearing molecules outside the Milky Way towards the nearby starburst Galaxy NGC 253. Methods. Using observations from the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory (ALCHEMI) project, we used the MAdrid Data CUBe Analysis package to model the emission of P-bearing molecules assuming local thermodynamic equilibrium (LTE) conditions. We also performed a non-LTE analysis using SpectralRadex. Results. We report the detection of a P-bearing molecule, phosphorus nitride (PN), for the first time in an extragalactic environment, towards two giant molecular clouds (GMCs) of NGC 253. The LTE analysis yields total PN beam-averaged column densities N = (1.20 +/- 0.09) x 10(13) cm(-2) and N = (6.5 +/- 1.6) x 10(12) cm(-2), which translate into abundances with respect to H-2 of chi = (8.0 +/- 1.0) x 10(-12) and chi = (4.4 +/- 1.2) x 10(-12). We derived a low excitation temperature of T-ex = (4.4 +/- 1.3) K towards the GMC with the brightest PN emission, which indicates that PN is sub-thermally excited. The non-LTE analysis results in column densities consistent with the LTE values. We also searched for other P-bearing molecules (PO, PH3, CP, and CCP), and upper limits were derived. The derived PO/PN ratios are < 1.3 and < 1.7. The abundance ratio between PN and the shock-tracer SiO derived towards NGC 253 follows the same trend previously found towards Galactic sources. Conclusions. Comparison of the observations with chemical models indicates that the derived molecular abundances of PN in NGC 253 can be explained by shock-driven chemistry followed by cosmic-ray-driven photochemistry.
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| 30. |
- Harada, N., et al.
(författare)
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ALCHEMI Finds a “Shocking” Carbon Footprint in the Starburst Galaxy NGC 253
- 2022
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 938:1
-
Tidskriftsartikel (refereegranskat)abstract
- The centers of starburst galaxies may be characterized by a specific gas and ice chemistry due to their gas dynamics and the presence of various ice desorption mechanisms. This may result in a peculiar observable composition. We analyse the abundances of CO2, a reliable tracer of ice chemistry, from data collected as part of the Atacama Large Millimeter/submillimeter Array large program ALCHEMI, a wide-frequency spectral scan toward the starburst galaxy NGC 253 with an angular resolution of 1.″6. We constrain the CO2 abundances in the gas phase using its protonated form HOCO+. The distribution of HOCO+ is similar to that of methanol, which suggests that HOCO+ is indeed produced from the protonation of CO2 sublimated from ice. The HOCO+ fractional abundances are found to be (1-2) × 10−9 at the outer part of the central molecular zone (CMZ), while they are lower (∼10−10) near the kinematic center. This peak fractional abundance at the outer CMZ is comparable to that in the Milky Way CMZ, and orders of magnitude higher than that in Galactic disk, star-forming regions. From the range of HOCO+/CO2 ratios suggested from chemical models, the gas-phase CO2 fractional abundance is estimated to be (1-20) × 10−7 at the outer CMZ, and orders of magnitude lower near the center. We estimate the CO2 ice fractional abundances at the outer CMZ to be (2-5) × 10−6 from the literature. A comparison between the ice and gas CO2 abundances suggests an efficient sublimation mechanism. This sublimation is attributed to large-scale shocks at the orbital intersections of the bar and CMZ.
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| 31. |
- Jasechko, S., et al.
(författare)
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Late-glacial to late-Holocene shifts in global precipitation delta O-18
- 2015
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Ingår i: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 11:10, s. 1375-1393
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Tidskriftsartikel (refereegranskat)abstract
- Reconstructions of Quaternary climate are often based on the isotopic content of paleo-precipitation preserved in proxy records. While many paleo-precipitation isotope records are available, few studies have synthesized these dispersed records to explore spatial patterns of late-glacial precipitation delta O-18. Here we present a synthesis of 86 globally distributed groundwater (n = 59), cave calcite (n = 15) and ice core (n = 12) isotope records spanning the late-glacial (defined as similar to 50 000 to similar to 20 000 years ago) to the late-Holocene (within the past similar to 5000 years). We show that precipitation delta O-18 changes from the late-glacial to the late-Holocene range from -7.1% (delta O-18(late-Holocene) > delta O-18(late-glacial)) to + 1.7% (delta O-18(late-glacial) > delta O-18(late-Holocene)), with the majority (77 %) of records having lower late-glacial delta O-18 than late-Holocene delta O-18 values. High-magnitude, negative precipitation delta O-18 shifts are common at high latitudes, high altitudes and continental interiors (delta O-18(late-Holocene) > delta O-18(late-glacial) by more than 3 %). Conversely, low-magnitude, positive precipitation delta O-18 shifts are concentrated along tropical and subtropical coasts (delta O-18(late-glacial) > delta O-18(late-Holocene) by less than 2 %). Broad, global patterns of late-glacial to late-Holocene precipitation delta O-18 shifts suggest that stronger-than-modern isotopic distillation of air masses prevailed during the late-glacial, likely impacted by larger global temperature differences between the tropics and the poles. Further, to test how well general circulation models reproduce global precipitation delta O-18 shifts, we compiled simulated precipitation delta O-18 shifts from five isotope-enabled general circulation models simulated under recent and last glacial maximum climate states. Climate simulations generally show better intermodel and model-measurement agreement in temperate regions than in the tropics, highlighting a need for further research to better understand how inter-model spread in convective rainout, seawater delta O-18 and glacial topography parameterizations impact simulated precipitation delta O-18. Future research on paleo-precipitation delta O-18 records can use the global maps of measured and simulated late-glacial precipitation isotope compositions to target and prioritize field sites.
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| 32. |
- Kanis, J A, et al.
(författare)
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The use of clinical risk factors enhances the performance of BMD in the prediction of hip and osteoporotic fractures in men and women.
- 2007
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Ingår i: Osteoporosis international. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 18:8, s. 1033-46
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Tidskriftsartikel (refereegranskat)abstract
- SUMMARY: BMD and clinical risk factors predict hip and other osteoporotic fractures. The combination of clinical risk factors and BMD provide higher specificity and sensitivity than either alone. INTRODUCTION AND HYPOTHESES: To develop a risk assessment tool based on clinical risk factors (CRFs) with and without BMD. METHODS: Nine population-based studies were studied in which BMD and CRFs were documented at baseline. Poisson regression models were developed for hip fracture and other osteoporotic fractures, with and without hip BMD. Fracture risk was expressed as gradient of risk (GR, risk ratio/SD change in risk score). RESULTS: CRFs alone predicted hip fracture with a GR of 2.1/SD at the age of 50 years and decreased with age. The use of BMD alone provided a higher GR (3.7/SD), and was improved further with the combined use of CRFs and BMD (4.2/SD). For other osteoporotic fractures, the GRs were lower than for hip fracture. The GR with CRFs alone was 1.4/SD at the age of 50 years, similar to that provided by BMD (GR = 1.4/SD) and was not markedly increased by the combination (GR = 1.4/SD). The performance characteristics of clinical risk factors with and without BMD were validated in eleven independent population-based cohorts. CONCLUSIONS: The models developed provide the basis for the integrated use of validated clinical risk factors in men and women to aid in fracture risk prediction.
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| 33. |
- Laporte, N., et al.
(författare)
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ALMA Lensing Cluster Survey: A strongly lensed multiply imaged dusty system at z ≥ 6
- 2021
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 505:4, s. 4838-4846
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Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of an intrinsically faint, quintuply-imaged, dusty galaxy MACS0600-z6 at a redshift z = 6.07 viewed through the cluster MACSJ0600.1–2008 (z = 0.46). A ≃ 4σ dust detection is seen at 1.2mm as part of the ALMA Lensing Cluster Survey (ALCS), an on-going ALMA Large programme, and the redshift is secured via [C II] 158 μm emission described in a companion paper. In addition, spectroscopic follow-up with GMOS/Gemini-North shows a break in the galaxy’s spectrum, consistent with the Lyman break at that redshift. We use a detailed mass model of the cluster and infer a magnification μ ≳ 30 for the most magnified image of this galaxy, which provides an unprecedented opportunity to probe the physical properties of a sub-luminous galaxy at the end of cosmic reionization. Based on the spectral energy distribution, we infer lensing-corrected stellar and dust masses of 2.9-2.3+115 × 109 and 4.8-3.4+45 × 106 M☉, respectively, a star formation rate of 9.7-6.6+220 M☉ yr−1, an intrinsic size of 0.54-0.14+026 kpc, and a luminosity-weighted age of 200 ± 100 Myr. Strikingly, the dust production rate in this relatively young galaxy appears to be larger than that observed for equivalent, lower redshift sources. We discuss if this implies that early supernovae are more efficient dust producers and the consequences for using dust mass as a probe of earlier star formation.
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| 34. |
- Nocerino, Elisabetta, et al.
(författare)
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Nuclear and magnetic spin structure of the antiferromagnetic triangular lattice compound LiCrTe 2 investigated by μ + SR, neutron and X-ray diffraction
- 2022
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional (2D) triangular lattice antiferromagnets (2D-TLA) often manifest intriguing physical and technological properties, due to the strong interplay between lattice geometry and electronic properties. The recently synthesized 2-dimensional transition metal dichalcogenide LiCrTe2, being a 2D-TLA, enriched the range of materials which can present such properties. In this work, muon spin rotation (μ+SR) and neutron powder diffraction (NPD) have been utilized to reveal the true magnetic nature and ground state of LiCrTe2. From high-resolution NPD the magnetic spin order at base-temperature is not, as previously suggested, helical, but rather collinear antiferromagnetic (AFM) with ferromagnetic (FM) spin coupling within the ab-plane and AFM coupling along the c-axis. The value if the ordered magnetic Cr moment is established as μCr=2.36μB. From detailed μ+SR measurements we observe an AFM ordering temperature TN≈ 125 K. This value is remarkably higher than the one previously reported by magnetic bulk measurements. From μ+SR we are able to extract the magnetic order parameter, whose critical exponent allows us to categorize LiCrTe2 in the 3D Heisenberg AFM universality class. Finally, by combining our magnetic studies with high-resolution synchrotron X-ray diffraction (XRD), we find a clear coupling between the nuclear and magnetic spin lattices. This suggests the possibility for a strong magnon–phonon coupling, similar to what has been previously observed in the closely related compound LiCrO2.
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| 35. |
- Proletov, Ian, et al.
(författare)
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Primary and secondary glomerulonephritides 1.
- 2014
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Ingår i: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. - : Oxford University Press (OUP). - 1460-2385. ; 29 Suppl 3:May, s. 186-200
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Tidskriftsartikel (refereegranskat)
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| 36. |
- Yamada, Y., et al.
(författare)
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Estimation of the amount of the proton injected into tungsten oxide thin films during deposition using spectroscopic ellipsometry
- 2007
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:7-8, s. 3825-3829
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Tidskriftsartikel (refereegranskat)abstract
- Tungsten oxide thin films injected with protons (HxWO3) during deposition were prepared on glass substrates using reactive direct-current magnetron sputtering in a mixture of argon, oxygen, and hydrogen gases. The as-deposited films were bronze. The amount of injected protons, namely the x-value in HxWO3, was estimated using the dispersion of the extinction coefficient (κ). The dispersion was evaluated by analyzing the experimental spectra measured with spectroscopic ellipsometry and optical photometry using the model composed of a homogeneous tungsten bronze layer with an additional surface roughness layer. As a result of analysis, the x-value was estimated to be approximately 0.1.
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| 37. |
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| 38. |
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| 39. |
- Almeida, Cristiane G., et al.
(författare)
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Photocatalytic hydrogen production with visible light over Mo and Cr-doped BiNb(Ta)O-4
- 2014
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 39:3, s. 1220-1227
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, we prepared pure and Cr(III) and Mo(V)-doped BiNbO4 and BiTaO4 by the citrate method. Pure BiNbO4 and BiTaO4 were obtained in triclinic phase at 600 degrees C and 800 degrees C, respectively. The metal doping influenced strongly the crystal structure as well as the photocatalytic activity of the oxides. The XRD data could prove that the Mo(V) doping induces the orthorhombic phase, while the Cr(III) doping favors the triclinic phase for both oxides. Metal doping also modified the photosensitivity of the oxides, extending the absorption toward the visible light region. The photocatalytic activity in water splitting under visible light irradiation was evaluated by monitoring the H-2, CO2 and CO evolution. The results showed that Cr(III)-doped BiTaO4 and BiNbO4, in general, are more selective for hydrogen production, while Mo(V)-doped materials are more selective for CO2 generation. Comparing the photocatalytic activity of BiTaO4 and BiNbO4, the former shows higher activity for hydrogen production as well as for CO2 generation, specially when the concentration was 2% in Cr(III) and Mo(V), respectively. Those results are in agreement with the computational study to access the effect of doping on the electronic structure. For Mo(V)-doped materials a negligible change of conduction band minimum potential was found, indicating that there might be no improvement on the reduction power of the material following the substitutional doping. In Cr(III)-doped BiNbO4 there is a slight shift of the CBM potential increasing a little bit the reduction power. However, the effect is much stronger in the Cr(III)-doped BiTaO4.
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| 40. |
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| 41. |
- Greenhalgh, David G., et al.
(författare)
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Surviving Sepsis After Burn Campaign
- 2023
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Ingår i: Burns. - : Elsevier. - 0305-4179 .- 1879-1409. ; 49:7, s. 1487-1524
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes. Methods: The International Society for Burn Injuries (ISBI) reached out to regional or na-tional burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and out-come" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC parti-cipants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported. Results: The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for in burn should be on a basis. Conclusion: Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients. (c) 2023 Elsevier Ltd and ISBI. All rights reserved.
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| 42. |
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| 43. |
- Harada, Nanase, et al.
(författare)
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Starburst Energy Feedback Seen through HCO+/HOC+ Emission in NGC 253 from ALCHEMI
- 2021
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 923:1
-
Tidskriftsartikel (refereegranskat)abstract
- Molecular abundances are sensitive to the UV photon flux and cosmic-ray ionization rate. In starburst environments, the effects of high-energy photons and particles are expected to be stronger. We examine these astrochemical signatures through multiple transitions of HCO+ and its metastable isomer HOC+ in the center of the starburst galaxy NGC 253 using data from the Atacama Large Millimeter/submillimeter Array large program ALMA Comprehensive High-resolution Extragalactic Molecular inventory. The distribution of the HOC+(1-0) integrated intensity shows its association with "superbubbles," cavities created either by supernovae or expanding H ii regions. The observed HCO+/HOC+ abundance ratios are similar to 10-150, and the fractional abundance of HOC+ relative to H-2 is similar to 1.5 x 10(-11)-6 x 10(-10), which implies that the HOC+ abundance in the center of NGC 253 is significantly higher than in quiescent spiral arm dark clouds in the Galaxy and the Galactic center clouds. Comparison with chemical models implies either an interstellar radiation field of G (0) greater than or similar to 10(3) if the maximum visual extinction is greater than or similar to 5, or a cosmic-ray ionization rate of zeta greater than or similar to 10(-14) s(-1) (3-4 orders of magnitude higher than that within clouds in the Galactic spiral arms) to reproduce the observed results. From the difference in formation routes of HOC+, we propose that a low-excitation line of HOC+ traces cosmic-ray dominated regions, while high-excitation lines trace photodissociation regions. Our results suggest that the interstellar medium in the center of NGC 253 is significantly affected by energy input from UV photons and cosmic rays, sources of energy feedback.
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| 44. |
- Higgins, Geoff S, et al.
(författare)
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A small interfering RNA screen of genes involved in DNA repair identifies tumor-specific radiosensitization by POLQ knockdown.
- 2010
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 70:7, s. 2984-93
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Tidskriftsartikel (refereegranskat)abstract
- The effectiveness of radiotherapy treatment could be significantly improved if tumor cells could be rendered more sensitive to ionizing radiation (IR) without altering the sensitivity of normal tissues. However, many of the key therapeutically exploitable mechanisms that determine intrinsic tumor radiosensitivity are largely unknown. We have conducted a small interfering RNA (siRNA) screen of 200 genes involved in DNA damage repair aimed at identifying genes whose knockdown increased tumor radiosensitivity. Parallel siRNA screens were conducted in irradiated and unirradiated tumor cells (SQ20B) and irradiated normal tissue cells (MRC5). Using gammaH2AX foci at 24 hours after IR, we identified several genes, such as BRCA2, Lig IV, and XRCC5, whose knockdown is known to cause increased cell radiosensitivity, thereby validating the primary screening end point. In addition, we identified POLQ (DNA polymerase ) as a potential tumor-specific target. Subsequent investigations showed that POLQ knockdown resulted in radiosensitization of a panel of tumor cell lines from different primary sites while having little or no effect on normal tissue cell lines. These findings raise the possibility that POLQ inhibition might be used clinically to cause tumor-specific radiosensitization.
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| 45. |
- Jin, P., et al.
(författare)
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Epitaxial growth of W-doped VO2/V2O3 multilayer on a-Al2O3(110) by reactive magnetron sputtering
- 2000
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Ingår i: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 375:1-2, s. 128-131
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Tidskriftsartikel (refereegranskat)abstract
- Multilayer epitaxy with a W-VO2 top layer over a bottom layer of which the crystal phase depends on the starting oxygen flow, was done on a-Al2O3(110) by reactively sputtering a V-W (1.6 at.% wt.) alloy target at linearly increasing oxygen flow without interrupting film growth. For the film deposited in the oxygen flow from 10 to 26 sccm, a W-VO2/W-V2O3 multilayer was formed on a-Al2O3(110) with the epitaxial relationship being (001)f?(110)s, (110)f?(001)s for W-V2O3, and (010)f?(110)s, (100)f?(001)s for W-VO2 where f and s denote the film and substrate, respectively. The formation of a triple domain structure was confirmed in the W-VO2 top layer due to the strong influence from the symmetry of the substrate. The multilayer shows phase transition behavior differing from the single layer film, which was presumably due to the effects of W-doping, compositional gradient, and strain.
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| 46. |
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| 47. |
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| 48. |
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| 49. |
- Orwoll, Eric S., et al.
(författare)
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Evidence for Geographical and Racial Variation in Serum Sex Steroid Levels in Older Men
- 2010
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 95:10, s. E151-E160
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Tidskriftsartikel (refereegranskat)abstract
- Background: Despite considerable racial and geographical differences in human phenotypes and in the incidence of diseases that may be associated with sex steroid action, there are few data concerning variation in sex steroid levels among populations. We designed an international study to determine the degree to which geography and race influence sex steroid levels in older men. Methods: Using mass spectrometry, concentrations of serum androgens, estrogens, and sex steroid precursors/metabolites were measured in 5003 older men from five countries. SHBG levels were assessed using radioimmunoassay. Results: There was substantial geographical variation in the levels of sex steroids, precursors, and metabolites, as well as SHBG. For instance, Asian men in Hong Kong and Japan, but not in the United States, had levels of total testosterone approximately 20% higher than in other groups. Even greater variation was present in levels of estradiol, SHBG, and dihydrotestosterone. Group differences in body mass index did not explain most geographical differences. In addition, body mass index-independent racial differences were present; Black men had higher levels of estrogens (estradiol, estrone), and Asian men had lower levels of glucuronidated androgen metabolites. Conclusions: On a global scale, there are important geographical and racial differences in the concentrations of serum sex steroids and SHBG in older men.
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