11. |
- Strawn, Clayton, et al.
(författare)
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The AGORA High-resolution Galaxy Simulations Comparison Project. VI. Similarities and Differences in the Circumgalactic Medium
- 2024
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Ingår i: Astrophysical Journal. - 0004-637X. ; 962:1
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the circumgalactic medium (CGM) for eight commonly-used cosmological codes in the AGORA collaboration. The codes are calibrated to use identical initial conditions, cosmology, heating and cooling, and star formation thresholds, but each evolves with its own unique code architecture and stellar feedback implementation. Here, we analyze the results of these simulations in terms of the structure, composition, and phase dynamics of the CGM. We show properties such as metal distribution, ionization levels, and kinematics are effective tracers of the effects of the different code feedback and implementation methods, and as such they can be highly divergent between simulations. This is merely a fiducial set of models, against which we will in the future compare multiple feedback recipes for each code. Nevertheless, we find that the large parameter space these simulations establish can help disentangle the different variables that affect observable quantities in the CGM, e.g., showing that abundances for ions with higher ionization energy are more strongly determined by the simulation’s metallicity, while abundances for ions with lower ionization energy are more strongly determined by the gas density and temperature.
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12. |
- Boya, K., et al.
(författare)
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Possible candidate for the realization of the floating phase in the S=5/2 frustrated spin-chain model : K3Fe(MoO4)2(Mo2O7 )
- 2024
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Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 109:15
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Tidskriftsartikel (refereegranskat)abstract
- The frustrated spin-chain (FSC) systems exhibit exotic ground states and distinct quantum phase transitions. The ?=1/2 FSC is known to exhibit the Kosterlitz-Thouless transition from a commensurate gapless phase to a fully dimerized gapped phase upon the ratio of next-nearest-neighbor to nearest-neighbor coupling (?=?2/?1) being tuned. On the other hand, the ?=5/2 FSC system is known to show transitions from a commensurate gapless phase to partially dimerized and incommensurate floating phases [Chepiga, Affleck, and Mila, Phys. Rev. B 105, 174402 (2022)]. While a large region of the floating phase has been theoretically predicted for the ?=5/2 FSC model when ?>0.43, it is yet to be explored experimentally. Here, we have investigated a compound K3Fe(MoO4)2(Mo2O7), having well-separated ?=5/2 FSCs. The electronic structure calculations show that the ?=?2/?1 is close to 0.9, being similar to another FSC compound Bi3FeMo2O12 (?≈1.1). No magnetic long-range order is found down to 0.09 K, despite the relatively sizable Curie-Weiss temperature ???=−18K. The magnetic heat capacity shows the power-law behavior, indicating that the compound exhibits gapless excitations. Based on the experimental results and the theoretical calculations employed by density functional theory, we argue that the titled system is a possible candidate for exhibiting the floating phase.
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13. |
- Caliskan, Etem, et al.
(författare)
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Saphenous vein grafts in contemporary coronary artery bypass graft surgery
- 2020
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Ingår i: Nature Reviews Cardiology. - : Nature Publishing Group. - 1759-5002 .- 1759-5010. ; 17:3, s. 155-169
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Forskningsöversikt (refereegranskat)abstract
- Myocardial ischaemia resulting from obstructive coronary artery disease is a major cause of morbidity and mortality in the developed world. Coronary artery bypass graft (CABG) surgery is the gold-standard treatment in many patients with complex multivessel coronary artery disease or left main disease. Despite substantial improvements in the outcome of patients undergoing CABG surgery in the past decade, graft patency remains the 'Achilles' heel' of this procedure. Whereas the use of the left internal mammary artery as a conduit is associated with the highest 10-year patency rate (>90%), saphenous vein grafts - the most commonly used conduit in CABG surgery - fail in 40-50% of treated patients by 10 years after surgery. Vein graft disease (VGD) and failure result from complex pathophysiological processes that can lead to complete occlusion of the graft, affecting long-term clinical outcomes. Optimal harvesting techniques, intraoperative preservation strategies and intraoperative patency control have important roles in the prevention of VGD. In addition, several studies published in the past decade have reported similar mid-term patency rates between vein grafts and arterial grafts when veins are used as a composite graft based on the internal mammary artery. In this Review, we present the latest evidence on the utilization of saphenous vein grafts for CABG surgery and provide an overview of the current practices for the prevention of VGD and vein graft failure.
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14. |
- Choi, Joong Il Jake, et al.
(författare)
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Surface Termination-Dependent Nanotribological Properties of Single-Crystal MAPbBr(3) Surfaces
- 2020
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Ingår i: The Journal of Physical Chemistry C. - : AMER CHEMICAL SOC. - 1932-7447 .- 1932-7455. ; 124:2, s. 1484-1491
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Tidskriftsartikel (refereegranskat)abstract
- Atomistic characterization of surface termination and the corresponding mechanical properties of single-crystal methylammonium lead tribromide (MAPbBr(3)) are performed using combined atomic force microscopy (AFM) measurements and density functional theory (DFT) calculations. A clean MAPbBr(3) surface is obtained by in situ cleavage in ultrahigh vacuum at room temperature, and the subsequent AFM measurements of the as-cleaved MAPbBr(3) exhibit the coexistence of two different surface terrace types with step height differences corresponding to about half the thickness of a PbI6 octahedron layer. Concurrent friction force microscopy measurements show that the two surfaces result in two distinct friction values. Based on DFT calculations, we attribute the higher-friction and lower-friction surfaces to MABr-terminated flat and PbBr2-terminated vacant surface terminations, respectively. The calculated electronic band structures of the various MABr- and PbBr2-terminated surfaces show that the midgap states are absent, revealing the defect-tolerant nature of the ideal single-crystal MAPbBr(3) surfaces.
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15. |
- De Groot, Natasja M.S., et al.
(författare)
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Critical appraisal of technologies to assess electrical activity during atrial fibrillation : a position paper from the European Heart Rhythm Association and European Society of Cardiology Working Group on eCardiology in collaboration with the Heart Rhythm Society, Asia Pacific Heart Rhythm Society, Latin American Heart Rhythm Society and Computing in Cardiology
- 2022
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Ingår i: Europace. - : Oxford University Press (OUP). - 1099-5129. ; 24:2, s. 313-330
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Forskningsöversikt (refereegranskat)abstract
- We aim to provide a critical appraisal of basic concepts underlying signal recording and processing technologies applied for (i) atrial fibrillation (AF) mapping to unravel AF mechanisms and/or identifying target sites for AF therapy and (ii) AF detection, to optimize usage of technologies, stimulate research aimed at closing knowledge gaps, and developing ideal AF recording and processing technologies. Recording and processing techniques for assessment of electrical activity during AF essential for diagnosis and guiding ablative therapy including body surface electrocardiograms (ECG) and endo- or epicardial electrograms (EGM) are evaluated. Discussion of (i) differences in uni-, bi-, and multi-polar (omnipolar/Laplacian) recording modes, (ii) impact of recording technologies on EGM morphology, (iii) global or local mapping using various types of EGM involving signal processing techniques including isochronal-, voltage- fractionation-, dipole density-, and rotor mapping, enabling derivation of parameters like atrial rate, entropy, conduction velocity/direction, (iv) value of epicardial and optical mapping, (v) AF detection by cardiac implantable electronic devices containing various detection algorithms applicable to stored EGMs, (vi) contribution of machine learning (ML) to further improvement of signals processing technologies. Recording and processing of EGM (or ECG) are the cornerstones of (body surface) mapping of AF. Currently available AF recording and processing technologies are mainly restricted to specific applications or have technological limitations. Improvements in AF mapping by obtaining highest fidelity source signals (e.g. catheter-electrode combinations) for signal processing (e.g. filtering, digitization, and noise elimination) is of utmost importance. Novel acquisition instruments (multi-polar catheters combined with improved physical modelling and ML techniques) will enable enhanced and automated interpretation of EGM recordings in the near future.
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16. |
- Huang, Tzu-Hao, et al.
(författare)
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Separating Si phases from diagenetically-modified sediments through sequential leaching.
- 2023
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Ingår i: Chemical Geology. - 0009-2541 .- 1872-6836.
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Tidskriftsartikel (refereegranskat)abstract
- Silicon (Si) phases such as biogenic silica, lithogenic silicate and authigenic silica/silicate in marine sediments provide valuable information about past Si cycling. Wet-chemical sequential leaching methods are often applied to extract different Si phases from marine sediments to study Si diagenetic processes in shallow subsurface. The potential of this method to separate Si phases from deeply-buried and diagenetically-modified sediments has not been systematically examined. We applied a sequential leaching protocol to drill core sediments retrieved from the Ulleung Basin, East/Japan Sea. We performed geochemical (elemental abundance and stable Si isotopes, δ30Si) and microscopic (X-ray diffraction and scanning electron microscope) analyses to monitor leaching efficiency in separating different Si phases. We show that, prior to alkaline leaching, applying weak acid is able to remove metal oxide and/or clay-like phases. The following Na2CO3 leaching, based on a commonly-adopted protocol, is able to dissolve some but not all diatoms. The results of elemental contents and δ30Si values of leachates suggest that, in diagenetically-modified sediments, either a longer digesting time or a harsher alkaline leaching is needed to dissolve all diatoms. This is attributed to increased resistance of diatoms to Na2CO3 leaching as a result of reduced surface area and/or improved SiO2 tetrahedron ordering during diagenetic processes over time and burial depths. Lithogenic silicate minerals can be dissolved by NaOH and potentially separated from diatoms if the latter is completely removed in the preceding leaching steps. Even if a trace amount of diatom is left undissolved in the NaOH leaching, it is still possible to separate the two through a mass balance calculation given the knowledge of composition for the two end-members. We conclude that a successful separation of Si phases in diagenetically modified sediments relies on the knowledge of elemental abundance and even δ30Si values of the leachates, as well as information such as species of Si-skeleton organisms, contents and maturation degree of biogenic silica.
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17. |
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18. |
- Kim, Hyunsu, et al.
(författare)
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Photo-Programmed Deformations in Rigid Liquid Crystalline Polymers Triggered by Body Temperature
- 2022
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Ingår i: Small. - : Wiley. - 1613-6829 .- 1613-6810. ; , s. 2203772-
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Deformations triggered by body heat are desirable in the context of shape-morphing applications because, under the majority of circumstances, the human body maintains a higher temperature than that of its surroundings. However, at present, this bioenergy-triggered action is primarily limited to soft polymeric networks. Thus, herein, the programming of body temperature-triggered deformations into rigid azobenzene-containing liquid crystalline polymers (azo-LCPs) with a glass-transition temperature of 100 °C is demonstrated. To achieve this, a mechano-assisted photo-programming strategy is used to create a metastable state with room-temperature stable residual stress, which is induced by the isomerization of azobenzene. The programmed rigid azo-LCP can undergo large-amplitude body temperature-triggered shape changes within minutes and can be regenerated without any performance degradation. By changing the programming photomasks and irradiation conditions employed, various 2D to 3D shape-morphing architectures, including folded clips, inch-worm structures, spiral structures, and snap-through motions are achieved. When programmed with polarized light, the proposed strategy results in domain-selective activation, generating designed characteristics in multi-domain azo-LCPs. The reported strategy is therefore expected to broaden the applications of azo-LCPs in the fields of biomedical and flexible microelectronic devices.
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19. |
- Kim, HoUng, et al.
(författare)
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The Future of Biosimilars : Maximizing Benefits Across Immune-Mediated Inflammatory Diseases
- 2020
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Ingår i: Drugs. - : Adis International. - 0012-6667 .- 1179-1950. ; 80:2, s. 99-113
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Tidskriftsartikel (refereegranskat)abstract
- Biologics have transformed the treatment of immune-mediated inflammatory diseases such as rheumatoid arthritis (RA) and inflammatory bowel disease (IBD). Biosimilars-biologic medicines with no clinically meaningful differences in safety or efficacy from licensed originators-can stimulate market competition and have the potential to expand patient access to biologics within the parameters of treatment recommendations. However, maximizing the benefits of biosimilars requires cooperation between multiple stakeholders. Regulators and developers should collaborate to ensure biosimilars reach patients rapidly without compromising stringent quality, safety, or efficacy standards. Pharmacoeconomic evaluations and payer policies should be updated following biosimilar market entry, minimizing the risk of imposing nonmedical barriers to biologic treatment. In RA, disparities between treatment guidelines and national reimbursement criteria could be addressed to ensure more uniform patient access to biologics and enable rheumatologists to effectively implement treat-to-target strategies. In IBD, the cost-effectiveness of biologic treatment earlier in the disease course is likely to improve when biosimilars are incorporated into pharmacoeconomic analyses. Patient understanding of biosimilars is crucial for treatment success and avoiding nocebo effects. Full understanding of biosimilars by physicians and carefully considered communication strategies can help support patients initiating or switching to biosimilars. Developers must operate efficiently to be sustainable, without undermining product quality, the reliability of the supply chain, or pharmacovigilance. Developers should also facilitate information sharing to meet the needs of other stakeholders. Such collaboration will help to ensure a sustainable future for both the biosimilar market and healthcare systems, supporting the availability of effective treatments for patients.
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20. |
- Kim, Ji-Hoon, et al.
(författare)
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A Pulse of Meteoric Subsurface Fluid Discharging Into the Chukchi Sea During the Early Holocene Thermal Maximum (EHTM)
- 2021
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Ingår i: Geochemistry Geophysics Geosystems. - 1525-2027. ; 22:8
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Tidskriftsartikel (refereegranskat)abstract
- The response of Arctic Ocean biogeochemistry to subsurface flow driven by permafrost thaw is poorly understood. We present dissolved chloride and water isotopic data from the Chukchi Sea Shelf sediments that reveal the presence of a meteoric subsurface flow enriched in cations with a radiogenic Sr fingerprint. This subsurface fluid is also enriched in dissolved inorganic carbon and methane that bear isotopic compositions indicative of a carbon reservoir modified by reactions in a closed system. Such fluid characteristics are in stark contrast with those from other sites in the Chukchi Sea where the pore water composition shows no sign of meteoric input, but reflect typical biogeochemical reactions associated with early diagenetic sequences in marine sediment. The most likely source of the observed subsurface flow at the Chukchi Sea Shelf is from the degradation of permafrost that had extended to the shelf region during the Last Glacial Maximum. Our data suggest that the permafrost-driven subsurface flow most likely took place during the 2-3 degrees C warming in the Early Holocene Thermal Maximum. This time scale is supported by numerical simulation of pore water profiles, which indicate that a minimum of several thousand years must have passed since the cessation of the subsurface methane-bearing fluid flow.
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