| 121. |
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| 122. |
- Taddia, Francesco, et al.
(författare)
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Early-time light curves of Type Ib/c supernovae from the SDSS-II Supernova Survey
- 2015
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 574
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Tidskriftsartikel (refereegranskat)abstract
- Context. Type Ib/c supernovae (SNe Ib/c) have been investigated in several single-object studies; however, there is still a paucity of works concerning larger, homogeneous samples of these hydrogen-poor transients, in particular regarding the premaximum phase of their light curves.Aims. In this paper we present and analyze the early-time optical light curves (LCs, ugriz) of 20 SNe Ib/c from the Sloan Digital Sky Survey (SDSS) SN survey II, aiming to study their observational and physical properties, as well as to derive their progenitor parameters.Methods. High-cadence, multiband LCs are fitted with a functional model and the best-fit parameters are compared among the SN types. Bolometric LCs (BLCs) are constructed for the entire sample. We also computed the black-body (BB) temperature (TBB) and photospheric radius (Rph) evolution for each SN via BB fits on the spectral energy distributions. In addition, the bolometric properties are compared to both hydrodynamical and analytical model expectations.Results. Complementing our sample with literature data, we find that SNe Ic and Ic-BL (broad-line) have shorter rise times than those of SNe Ib and IIb. The decline rate parameter, Δm15, is similar among the different subtypes. SNe Ic appear brighter and bluer than SNe Ib, but this difference vanishes if we consider host galaxy extinction corrections based on colors. Templates for SN Ib/c LCs are presented. Our SNe have typical TBB of ~10 000 K at the peak and Rph of ~1015 cm. Analysis of the BLCs of SNe Ib and Ic gives typical ejecta masses Mej≈ 3.6−5.7 M⊙, energies EK≈ 1.5−1.7×1051 erg, and M(56Ni) ≈ 0.3 M⊙. Higher values for EK and M(56Ni) are estimated for SNe Ic-BL (Mej≈ 5.4 M⊙, EK≈ 10.7×1051 erg, M(56Ni) ≈ 1.1 M⊙). For the majority of SNe Ic and Ic-BL, we can put strong limits (<2−4 days) on the duration of the expected early-time plateau. Less stringent limits can be placed on the duration of the plateau for the sample of SNe Ib. In the single case of SN Ib 2006lc, a >5.9 days plateau seems to be detected. The rising part of the BLCs is reproduced by power laws with index <2. For two events (SN 2005hm and SN 2007qx), we find signatures of a possible shock break-out cooling tail.Conclusions. Based on the limits for the plateau length and on the slow rise of the BLCs, we find that in most of our SNe Ic and Ic-BL the 56Ni is mixed out to the outer layers, suggesting that SN Ic progenitors are de facto helium poor. The derived progenitor parameters (56Ni, EK, Mej) are consistent with previous works.
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| 123. |
- Takamiya, Akihiro, et al.
(författare)
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Neural Substrates of Psychotic Depression : Findings From the Global ECT-MRI Research Collaboration
- 2022
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Ingår i: Schizophrenia Bulletin. - : Oxford University Press. - 0586-7614 .- 1745-1701. ; 48:2, s. 514-523
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Tidskriftsartikel (refereegranskat)abstract
- Psychotic major depression (PMD) is hypothesized to be a distinct clinical entity from nonpsychotic major depression (NPMD). However, neurobiological evidence supporting this notion is scarce. The aim of this study is to identify gray matter volume (GMV) differences between PMD and NPMD and their longitudinal change following electroconvulsive therapy (ECT). Structural magnetic resonance imaging (MRI) data from 8 independent sites in the Global ECT-MRI Research Collaboration (GEMRIC) database (n = 108; 56 PMD and 52 NPMD; mean age 71.7 in PMD and 70.2 in NPMD) were analyzed. All participants underwent MRI before and after ECT. First, cross-sectional whole-brain voxel-wise GMV comparisons between PMD and NPMD were conducted at both time points. Second, in a flexible factorial model, a main effect of time and a group-by-time interaction were examined to identify longitudinal effects of ECT on GMV and longitudinal differential effects of ECT between PMD and NPMD, respectively. Compared with NPMD, PMD showed lower GMV in the prefrontal, temporal and parietal cortex before ECT; PMD showed lower GMV in the medial prefrontal cortex (MPFC) after ECT. Although there was a significant main effect of time on GMV in several brain regions in both PMD and NPMD, there was no significant group-by-time interaction. Lower GMV in the MPFC was consistently identified in PMD, suggesting this may be a trait-like neural substrate of PMD. Longitudinal effect of ECT on GMV may not explain superior ECT response in PMD, and further investigation is needed.
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| 124. |
- Teitel, J, et al.
(författare)
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A consensus statement on clinical trials of bypassing agent prophylaxis in inhibitor patients.
- 2011
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Ingår i: Haemophilia. - : Wiley. - 1351-8216. ; 17, s. 516-521
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Tidskriftsartikel (refereegranskat)abstract
- Summary. The haemophilia literature increasingly contains reports describing the use of bypassing agent prophylaxis (BAP) in patients with severe haemophilia A and inhibitors. However, it is difficult to interpret and compare the results and draw conclusions about treatment efficacy because of small patient numbers and a lack of standardization among BAP studies. This article presents consensus recommendations for standardizing future BAP clinical trials developed by an international panel of haemophilia opinion leaders.
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| 125. |
- Thienel, Manuela, et al.
(författare)
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Immobility-associated thromboprotection is conserved across mammalian species from bear to human
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6641, s. 178-187
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Tidskriftsartikel (refereegranskat)abstract
- Venous thromboembolism (VTE) comprising deep venous thrombosis and pulmonary embolism is a major cause of morbidity and mortality. Short-term immobility-related conditions are a major risk factor for the development of VTE. Paradoxically, long-term immobilized free-ranging hibernating brown bears and paralyzed spinal cord injury (SCI) patients are protected from VTE. We aimed to identify mechanisms of immobility-associated VTE protection in a cross-species approach. Mass spectrometry-based proteomics revealed an antithrombotic signature in platelets of hibernating brown bears with heat shock protein 47 (HSP47) as the most substantially reduced protein. HSP47 down-regulation or ablation attenuated immune cell activation and neutrophil extracellular trap formation, contributing to thromboprotection in bears, SCI patients, and mice. This cross-species conserved platelet signature may give rise to antithrombotic therapeutics and prognostic markers beyond immobility-associated VTE.
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| 126. |
- West, Jay B., et al.
(författare)
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Comparison and evaluation of retrospective intermodality image registration techniques
- 1997
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Ingår i: SPIE - The International Society for Optical Engineering. - : SPIE - International Society for Optical Engineering. ; , s. 332-347
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Konferensbidrag (refereegranskat)abstract
- All retrospective image registration methods have attached to them some intrinsic estimate of registration error. However, this estimate of accuracy may not always be a good indicator of the distance between actual and estimated positions of targets within the cranial cavity. This paper describes a project whose principal goal is to use a prospective method based on fiducial markers as a ’gold standard’ to perform an objective, blinded evaluation of the accuracy of several retrospective image-to-image registration techniques. Image volumes of three modalities – CT, MR, and PET – were taken of patients undergoing neurosurgery at Vanderbilt University Medical Center. These volumes had all traces of the fiducial markers removed, and were provided to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR, and communicated their transformations to Vanderbilt where the accuracy of each registration was evaluated. In this evaluation the accuracy is measured at multiple ’regions of interest,’ i.e. areas in the brain which would commonly be areas of neurological interest. A region is defined in the MR image and its centroid C is determined. Then the prospective registration is used to obtain the corresponding point C’ in CT or PET. To this point the retrospective registration is then applied, producing C’ in MR. Statistics are gathered on the target registration error (TRE), which is the disparity between the original point C and its corresponding point C’. A second goal of the project is to evaluate the importance of correcting geometrical distortion in MR images, by comparing the retrospective TRE in the rectified images, i.e., those which have had the distortion correction applied, with that of the same images before rectification. This paper presents preliminary results of this study along with a brief description of each registration technique and an estimate of both preparation and execution time needed to perform the registration.
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| 127. |
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| 128. |
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| 129. |
- Winkler, MJ, et al.
(författare)
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Functional investigation of the coronary artery disease gene SVEP1
- 2020
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Ingår i: Basic research in cardiology. - : Springer Science and Business Media LLC. - 1435-1803 .- 0300-8428. ; 115:6, s. 67-
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Tidskriftsartikel (refereegranskat)abstract
- A missense variant of the sushi, von Willebrand factor type A, EGF and pentraxin domain containing protein 1 (SVEP1) is genome-wide significantly associated with coronary artery disease. The mechanisms how SVEP1 impacts atherosclerosis are not known. We found endothelial cells (EC) and vascular smooth muscle cells to represent the major cellular source of SVEP1 in plaques. Plaques were larger in atherosclerosis-prone Svep1 haploinsufficient (ApoE−/−Svep1+/−) compared to Svep1 wild-type mice (ApoE−/−Svep1+/+) and ApoE−/−Svep1+/− mice displayed elevated plaque neutrophil, Ly6Chigh monocyte, and macrophage numbers. We assessed how leukocytes accumulated more inside plaques in ApoE−/−Svep1+/− mice and found enhanced leukocyte recruitment from blood into plaques. In vitro, we examined how SVEP1 deficiency promotes leukocyte recruitment and found elevated expression of the leukocyte attractant chemokine (C-X-C motif) ligand 1 (CXCL1) in EC after incubation with missense compared to wild-type SVEP1. Increasing wild-type SVEP1 levels silenced endothelial CXCL1 release. In line, plasma Cxcl1 levels were elevated in ApoE−/−Svep1+/− mice. Our studies reveal an atheroprotective role of SVEP1. Deficiency of wild-type Svep1 increased endothelial CXCL1 expression leading to enhanced recruitment of proinflammatory leukocytes from blood to plaque. Consequently, elevated vascular inflammation resulted in enhanced plaque progression in Svep1 deficiency.
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