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- Almeida, João R.M., et al.
(författare)
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Physiological and Molecular Characterization of Yeast Cultures Pre-Adapted for Fermentation of Lignocellulosic Hydrolysate
- 2023
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Ingår i: Fermentation. - : MDPI AG. - 2311-5637. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Economically feasible bioethanol process from lignocellulose requires efficient fermentation by yeast of all sugars present in the hydrolysate. However, when exposed to lignocellulosic hydrolysate, Saccharomyces cerevisiae is challenged with a variety of inhibitors that reduce yeast viability, growth, and fermentation rate, and in addition damage cellular structures. In order to evaluate the capability of S. cerevisiae to adapt and respond to lignocellulosic hydrolysates, the physiological effect of cultivating yeast in the spruce hydrolysate was comprehensively studied by assessment of yeast performance in simultaneous saccharification and fermentation (SSF), measurement of furaldehyde reduction activity, assessment of conversion of phenolic compounds and genome-wide transcription analysis. The yeast cultivated in spruce hydrolysate developed a rapid adaptive response to lignocellulosic hydrolysate, which significantly improved its fermentation performance in subsequent SSF experiments. The adaptation was shown to involve the induction of NADPH-dependent aldehyde reductases and conversion of phenolic compounds during the fed-batch cultivation. These properties were correlated to the expression of several genes encoding oxidoreductases, notably AAD4, ADH6, OYE2/3, and YML131w. The other most significant transcriptional changes involved genes involved in transport mechanisms, such as YHK8, FLR1, or ATR1. A large set of genes were found to be associated with transcription factors (TFs) involved in stress response (Msn2p, Msn4p, Yap1p) but also cell growth and division (Gcr4p, Ste12p, Sok2p), and these TFs were most likely controlling the response at the post-transcriptional level.
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- Bahr, A., et al.
(författare)
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Non-reactive HiPIMS deposition of NbCx thin films : Effect of the target power density on structure-mechanical properties
- 2022
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Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 444
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Tidskriftsartikel (refereegranskat)abstract
- The exceptional mechanical properties of transition metal carbide coatings are known to be governed by the carbon content and its morphological distribution. Here, we verify the influence of the target peak power density on the chemical composition, microstructure, and mechanical properties of NbCx coatings grown by non-reactive high-power impulse magnetron sputtering (HiPIMS). By tuning the pulse parameters, the power density can be increased from 0.11 to 1.48 kW/cm2 leading to a decrease in the C/Nb ratio from 1.52 to 0.99 within the films - proven by combined elastic backscattering and time-of-flight elastic recoil detection analysis. This decrease in the C/Nb ratio is accompanied by microstructural changes from nanocomposite morphologies with an average grain size of 6.6 +/- 2.5 nm at 0.13 kW/cm2 into more columnar structures with an average column width of 65.2 +/- 18.7 nm at 1.48 kW/cm2. Independent from the C/Nb ratio, all films exhibit a single face-centered cubic structure. The mechanical properties correlate with the enhanced growth behavior dominated by ions at higher peak power densities and the varied C/Nb ratios. A maximum in hardness and fracture toughness of H = 38.7 +/- 3.6 GPa and KIc = 2.78 +/- 0.13 MPa center dot m1/2 (at 3.2 GPa residual compressive stress), is obtained for the nearly stoichiometric NbC coating exhibiting C/Nb ratio of 1.06.
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- Ben-Ami, Sagi, et al.
(författare)
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ULTRAVIOLET SPECTROSCOPY OF TYPE IIB SUPERNOVAE : DIVERSITY AND THE IMPACT OF CIRCUMSTELLAR MATERIAL
- 2015
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 803:1
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Tidskriftsartikel (refereegranskat)abstract
- We present new Hubble Space Telescope (HST) multi-epoch ultraviolet (UV) spectra of the bright Type IIb SN 2013df, and undertake a comprehensive analysis of the set of four SNe IIb for which HST UV spectra are available (SN 1993J, SN 2001ig, SN 2011dh, and SN 2013df). We find strong diversity in both continuum levels and line features among these objects. We use radiative-transfer models that fit the optical part of the spectrum well, and find that in three of these four events we see a UV continuum flux excess, apparently unaffected by line absorption. We hypothesize that this emission originates above the photosphere, and is related to interaction with circumstellar material (CSM) located in close proximity to the SN progenitor. In contrast, the spectra of SN 2001ig are well fit by single-temperature models, display weak continuum and strong reverse-fluorescence features, and are similar to spectra of radioactive 56Ni-dominated SNe Ia. A comparison of the early shock-cooling components in the observed light curves with the UV continuum levels which we assume trace the strength of CSM interaction suggests that events with slower cooling have stronger CSM emission. The radio emission from events having a prominent UV excess is perhaps consistent with slower blast-wave velocities, as expected if the explosion shock was slowed down by the CSM that is also responsible for the strong UV, but this connection is currently speculative as it is based on only a few events.
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- Blasche, Sonja, et al.
(författare)
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Metabolic cooperation and spatiotemporal niche partitioning in a kefir microbial community
- 2021
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Ingår i: Nature Microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 6:2, s. 196-208
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Tidskriftsartikel (refereegranskat)abstract
- Microbial communities often undergo intricate compositional changes yet also maintain stable coexistence of diverse species. The mechanisms underlying long-term coexistence remain unclear as system-wide studies have been largely limited to engineered communities, ex situ adapted cultures or synthetic assemblies. Here, we show how kefir, a natural milk-fermenting community of prokaryotes (predominantly lactic and acetic acid bacteria) and yeasts (family Saccharomycetaceae), realizes stable coexistence through spatiotemporal orchestration of species and metabolite dynamics. During milk fermentation, kefir grains (a polysaccharide matrix synthesized by kefir microorganisms) grow in mass but remain unchanged in composition. In contrast, the milk is colonized in a sequential manner in which early members open the niche for the followers by making available metabolites such as amino acids and lactate. Through metabolomics, transcriptomics and large-scale mapping of inter-species interactions, we show how microorganisms poorly suited for milk survive in—and even dominate—the community, through metabolic cooperation and uneven partitioning between grain and milk. Overall, our findings reveal how inter-species interactions partitioned in space and time lead to stable coexistence.
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- Campbell, Charles, et al.
(författare)
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Bridging model and real catalysts: general discussion
- 2016
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Ingår i: Faraday Discussions. - 1359-6640 .- 1364-5498. ; 188, s. 565-589
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Charles Campbell opened the discussion of the paper by Hans-JoachimFreund: If you have a 3D gold particle and it spreads out to be a 2D particle whenyou adsorb CO2, it must gain energy stability. Did you estimate the energy changeof the overall process to do that?
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- Cortez, Daniel, et al.
(författare)
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Noninvasive predictors of perioperative atrial arrhythmias in patients with tetralogy of Fallot undergoing pulmonary valve replacement
- 2017
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289. ; 40:8, s. 591-596
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with tetralogy of Fallot (TOF) have increased risk of atrial arrhythmias. Hypothesis: A measure of atrial dispersion, the P-wave vector magnitude (Pvm), can identify patients at risk for perioperative atrial flutter (AFL) or intra-atrial re-entrant tachycardia (IART) in a large TOF cohort. Methods: We performed a blinded, retrospective analysis of 158 TOF patients undergoing pulmonary valve replacement between 1997 and 2015. History of AFL/IART was documented using electrocardiogram, Holter monitor, exercise stress test, implanted cardiac device, and electrophysiology study. P-R intervals, Pvm, QRS duration, and QRS vector magnitude were assessed from resting sinus-rhythm 12-lead electrocardiograms and identification of those with AFL/IART was determined. Results: Fourteen patients (8.9%) were found to have AFL/IART. Pvm, QRS duration, and QRS vector magnitude significantly differentiated those with AFL/IART from those without on univariate analysis: 0.09±0.04 vs 0.18±0.07 mV, 161.3±21.9 vs 137.7±31.4ms, and 1.2 (interquartile range, 1.0-1.2) vs 1.6 mV (1.0-2.3), respectively (P < 0.05 for each). The Pvm had the highest area under the ROC curve (0.88) and was the only significant predictor on multivariate analysis, with odds ratio of 0.02 (95% confidence interval: 0.01-0.53). P-R duration, MRI volumes, and right-heart hemodynamics did not significantly differentiate those with vs those without AFL/IART. Conclusions: In TOF patients undergoing pulmonary valve replacement, Pvm has significant value in predicting those with perioperative AFL/IART. These clinical features may help further evaluate TOF patients at risk for perioperative atrial arrhythmias. Prospective studies are warranted.
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- Cortez, Daniel, et al.
(författare)
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Noninvasive Predictors of Ventricular Arrhythmias in Patients With Tetralogy of Fallot Undergoing Pulmonary Valve Replacement
- 2017
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Ingår i: JACC: Clinical Electrophysiology. - : Elsevier BV. - 2405-500X. ; 3:2, s. 162-170
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study sought to test the hypothesis that a vectorcardiographic parameter, the QRS vector magnitude (QRSVm), can risk stratify those patients at risk for sustained spontaneous ventricular arrhythmias (VAs) or ventricular arrhythmia inducibility (VAI) in a large cohort of patients with tetralogy of Fallot (TOF). Background: Patients with TOF have an increased risk of VAs, but predicting those at risk can often be challenging. Methods: Blinded retrospective analyses of 177 TOF patients undergoing pulmonary valve replacement (PVR) between 1997 and 2015 were performed. VAI was evaluated by programmed electrical stimulation in 48 patients. QRS intervals and QRSVm voltage measurements were assessed from resting 12-lead electrocardiograms, and risk of VA was determined. Clinical characteristics, including imaging and cardiac catheterizations, were used for other modality comparisons. Results: Sustained spontaneous VA occurred in 12 patients and inducible VA in 18 patients. Age and QRSVm were significant univariate predictors of VA. QRSVm was the only independent predictor of VAI (p < 0.001). Using a root mean square QRS value of 1.24 mV, the positive and negative predictive values were 47.9% and 97.8%, respectively, for spontaneous sustained VA. For VAI, using a QRSVm cutoff of 1.31 mV, positive and negative predictive values were 63.0% and 95.3%, respectively. Conclusions: In TOF patients undergoing PVR, older age was associated with increased spontaneous VA risk. Lower QRSVm predicted spontaneous VA or VAI risk with high negative predictive values. QRSVm is the only independent predictor of VAI. These clinical features may help further risk stratify TOF patients requiring therapies to prevent sudden death.
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- Frieler, Katja, et al.
(författare)
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Scenario setup and forcing data for impact model evaluation and impact attribution within the third round of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a)
- 2024
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Ingår i: Geoscientific Model Development. - : Copernicus Publications. - 1991-959X .- 1991-9603. ; 17:1, s. 1-51
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the rationale and the protocol of the first component of the third simulation round of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a, http://www.isimip.org, last access: 2 November 2023) and the associated set of climate-related and direct human forcing data (CRF and DHF, respectively). The observation-based climate-related forcings for the first time include high-resolution observational climate forcings derived by orographic downscaling, monthly to hourly coastal water levels, and wind fields associated with historical tropical cyclones. The DHFs include land use patterns, population densities, information about water and agricultural management, and fishing intensities. The ISIMIP3a impact model simulations driven by these observation-based climate-related and direct human forcings are designed to test to what degree the impact models can explain observed changes in natural and human systems. In a second set of ISIMIP3a experiments the participating impact models are forced by the same DHFs but a counterfactual set of atmospheric forcings and coastal water levels where observed trends have been removed. These experiments are designed to allow for the attribution of observed changes in natural, human, and managed systems to climate change, rising CH4 and CO2 concentrations, and sea level rise according to the definition of the Working Group II contribution to the IPCC AR6.
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- Johansson, Henrik J., et al.
(författare)
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Breast cancer quantitative proteome and proteogenomic landscape
- 2019
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- In the preceding decades, molecular characterization has revolutionized breast cancer (BC) research and therapeutic approaches. Presented herein, an unbiased analysis of breast tumor proteomes, inclusive of 9995 proteins quantified across all tumors, for the first time recapitulates BC subtypes. Additionally, poor-prognosis basal-like and luminal B tumors are further subdivided by immune component infiltration, suggesting the current classification is incomplete. Proteome-based networks distinguish functional protein modules for breast tumor groups, with co-expression of EGFR and MET marking ductal carcinoma in situ regions of normal-like tumors and lending to a more accurate classification of this poorly defined subtype. Genes included within prognostic mRNA panels have significantly higher than average mRNA-protein correlations, and gene copy number alterations are dampened at the protein-level; underscoring the value of proteome quantification for prognostication and phenotypic classification. Furthermore, protein products mapping to non-coding genomic regions are identified; highlighting a potential new class of tumor-specific immunotherapeutic targets.
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