| 1. |
- Jung, Christian, et al.
(författare)
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A comparison of very old patients admitted to intensive care unit after acute versus elective surgery or intervention
- 2019
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Ingår i: Journal of critical care. - : W B SAUNDERS CO-ELSEVIER INC. - 0883-9441 .- 1557-8615. ; 52, s. 141-148
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Tidskriftsartikel (refereegranskat)abstract
- Background: We aimed to evaluate differences in outcome between patients admitted to intensive care unit (ICU) after elective versus acute surgery in a multinational cohort of very old patients (80 years; VIP). Predictors of mortality, with special emphasis on frailty, were assessed.Methods: In total, 5063 VIPs were induded in this analysis, 922 were admitted after elective surgery or intervention, 4141 acutely, with 402 after acute surgery. Differences were calculated using Mann-Whitney-U test and Wilcoxon test. Univariate and multivariable logistic regression were used to assess associations with mortality.Results: Compared patients admitted after acute surgery, patients admitted after elective surgery suffered less often from frailty as defined as CFS (28% vs 46%; p < 0.001), evidenced lower SOFA scores (4 +/- 5 vs 7 +/- 7; p < 0.001). Presence of frailty (CFS >4) was associated with significantly increased mortality both in elective surgery patients (7% vs 12%; p = 0.01), in acute surgery (7% vs 12%; p = 0.02).Conclusions: VIPs admitted to ICU after elective surgery evidenced favorable outcome over patients after acute surgery even after correction for relevant confounders. Frailty might be used to guide clinicians in risk stratification in both patients admitted after elective and acute surgery.
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| 2. |
- Liu, Jiahui, et al.
(författare)
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Highly Porous Metalloporphyrin Covalent Ionic Frameworks with Well-Defined Cooperative Functional Groups as Excellent Catalysts for CO2 Cycloaddition
- 2019
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Ingår i: Chemistry - A European Journal. - : WILEY-V C H VERLAG GMBH. - 0947-6539 .- 1521-3765. ; 25:38, s. 9052-9059
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Tidskriftsartikel (refereegranskat)abstract
- The development of multifunctional heterogeneous catalysts with high porosity and remarkable catalytic activity still remains a challenge. Herein, four highly porous metalloporphyrin covalent ionic frameworks (CIFs) were synthesized by coupling 5,10,15,20-tetrakis(4-nitrophenyl)porphyrin (TNPP) with 3,8-diamino-6-phenylphenanithridine (NPPN) or 5,5 '-diamino-2,2 '-bipyridine (NBPy) followed by ionization with bromoethane (C2H5Br) or dibromoethane (C2H4Br2) and then metalization with Zn or Co. The resulting CIFs showed high efficiency in catalyzing the cycloaddition of propylene oxide (PO) with CO2 to form propylene carbonate (PC). All of the Zn-containing CIF catalysts were able to catalyze the cycloaddition reaction with a PC yield greater than 97 %. The TNPP/NBPy (CIF2) catalyst ionized with C2H4Br2 and metalized with Zn (Zn-CIF2-C2H4) exhibited the highest catalytic activity among the synthesized catalysts. The high catalytic performance of Zn-CIF2-C2H4 is related to its high porosity (577 m(2) g(-1)), high Br:metal ratio (1:3.89), and excellent synergistic action between the Lewis acidic Zn sites and the nucleophilic Br- ions. Zn-CIF2-C2H4 is sufficiently stable that greater than 94 % PC yield could be obtained even after six cycles. In addition, Zn-CIF2-C2H4 could catalyze the cycloaddition of several other epoxides with CO2. These highly porous materials are promising multifunctional and efficient catalysts for industrially relevant reactions.
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| 3. |
- von Sydow, Lina, et al.
(författare)
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BENCHOP—The BENCHmarking project in Option Pricing
- 2015
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Ingår i: International Journal of Computer Mathematics. - : Informa UK Limited. - 1029-0265 .- 0020-7160. ; 92:12, s. 2361-2379
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the BENCHOP project is to provide the finance community with a common suite of benchmark problems for option pricing. We provide a detailed description of the six benchmark problems together with methods to compute reference solutions. We have implemented seventeen different numerical methods for these problems, and compare their relative performance. All implementations are available on line and can be used for future development and comparisons.
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| 4. |
- Yuan, Zhao, et al.
(författare)
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Applying High Performance Computing to Probabilistic Convex Optimal Power Flow
- 2016
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Ingår i: 2016 INTERNATIONAL CONFERENCE ON PROBABILISTIC METHODS APPLIED TO POWER SYSTEMS (PMAPS). - : IEEE. - 9781509019700
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Konferensbidrag (refereegranskat)abstract
- The issue of applying high performance computing (HPC) techniques to computation-intensive probabilistic optimal power flow has not been well discussed in literature. In this paper, the probabilistic convex AC OPF based on second order cone programming (P-SOCPF) is formulated. The application of P-SOCPF is demonstrated by accounting uncertainties of loads. To estimate the distributions of nodal prices calculated from PSOCPF, two point estimation method (2PEM) is deployed. By comparing with Monte Carlo (MC) method, the accuracy of 2PEM is proved numerically. The computation efficiency of 2PEM outperforms MC significantly. In the context of large scale estimation, we propose to apply high performance computing (HPC) to P-SOCPF. The HPC accelerated P-SOCPF is implemented in GAMS grid computing environment. A flexible parallel management algorithm is designed to assign execution threads to different CPUs and then collect completed solutions. Numerical results from IEEE 118-bus and modified 1354pegase case network demonstrate that grid computing is effective means to speed up large scale P-SOCPF computation. The speed up of P-SOCPF computation is approximately equal to the number of cores in the computation node.
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| 5. |
- Zhang, Tianmeng, et al.
(författare)
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Observations of a Fast-expanding and UV-bright Type Ia Supernova SN 2013gs
- 2019
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 872:1
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present extensive optical and ultraviolet (UV) observations of the type Ia supernova (SN Ia) 2013gs discovered during the Tsinghua-NAOC Transient Survey. The photometric observations in the optical show that the light curves of SN 2013gs are similar to those of normal SNe Ia, with an absolute peak magnitude of M-B = -19.25 +/- 0.15 mag and a post-maximum decline rate Delta m(15)(B) = 1.00 +/- 0.05 mag. Gehrels Swift Ultr-Violet/Optical Telescope observations indicate that SN 2013gs shows unusually strong UV emission (especially in the uvw1 band) at around the maximum light (M-uvw1 similar to -18.9 mag). The SN is characterized by relatively weak Fe II III absorptions at similar to 5000 angstrom in the early spectra and a larger expansion velocity (v(Si) similar to 13,000 km s(-1) around the maximum light) than the normal-velocity SNe Ia. We discuss the relation between the uvw1 - v color and some observables, including Si II velocity, line strength of Si II lambda 6355 and Fe II/III lines, and Delta m(15)(B). Compared to other fast-expanding SNe Ia, SN 2013gs exhibits Si and Fe absorption lines with similar strength and bluer uvw1 - v color. We briefly discussed the origin of the observed UV dispersion of SNe Ia.
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