| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Morawska, Lidia, et al.
(författare)
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The state of science on severe air pollution episodes : Quantitative and qualitative analysis
- 2021
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Ingår i: Environment International. - : Elsevier BV. - 1873-6750 .- 0160-4120. ; 156, s. 106732-106732
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Tidskriftsartikel (refereegranskat)abstract
- Severe episodic air pollution blankets entire cities and regions and have a profound impact on humans and their activities. We compiled daily fine particle (PM2.5) data from 100 cities in five continents, investigated the trends of number, frequency, and duration of pollution episodes, and compared these with the baseline trend in air pollution. We showed that the factors contributing to these events are complex; however, long-term measures to abate emissions from all anthropogenic sources at all times is also the most efficient way to reduce the occurrence of severe air pollution events. In the short term, accurate forecasting systems of such events based on the meteorological conditions favouring their occurrence, together with effective emergency mitigation of anthropogenic sources, may lessen their magnitude and/or duration. However, there is no clear way of preventing events caused by natural sources affected by climate change, such as wildfires and desert dust outbreaks.
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| 3. |
- Sai, Hanna, et al.
(författare)
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Observations of the very young Type Ia Supernova 2019np with early-excess emission
- 2022
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 514:3, s. 3541-3558
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Tidskriftsartikel (refereegranskat)abstract
- Early-time radiative signals from Type Ia supernovae (SNe Ia) can provide important constraints on the explosion mechanism and the progenitor system. We present observations and analysis of SN 2019np, a nearby SN Ia discovered within 1–2 days after the explosion. Follow-up observations were conducted in optical, ultraviolet, and near-infrared bands, covering the phases from ∼−16.7 d to ∼+ 367.8 d relative to its B-band peak luminosity. The photometric and spectral evolutions of SN 2019np resemble the average behaviour of normal SNe Ia. The absolute B-band peak magnitude and the post-peak decline rate are Mmax(B) = −19.52 ± 0.47 mag and Δm15(B) = 1.04 ± 0.04 mag, respectively. No Hydrogen line has been detected in the nebular-phase spectra of SN 2019np. Assuming that the 56Ni powering the light curve is centrally located, we find that the bolometric light curve of SN 2019np shows a flux excess up to 5.0 per cent in the early phase compared to the radiative diffusion model. Such an extra radiation perhaps suggests the presence of an additional energy source beyond the radioactive decay of central nickel. Comparing the observed colour evolution with that predicted by different models, such as interactions of SN ejecta with circumstellar matter (CSM)/companion star, a double-detonation explosion from a sub-Chandrasekhar mass white dwarf (WD) and surface 56Ni mixing, we propose that the nickel mixing is more favoured for SN 2019np.
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| 4. |
- Hao, Zhengming, et al.
(författare)
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From n-alkane to polyacetylene on Cu (110): Linkage modulation in chain growth
- 2022
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Ingår i: Science in China Series B. - : SCIENCE PRESS. - 1674-7291 .- 1869-1870. ; 65:4, s. 733-739
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Tidskriftsartikel (refereegranskat)abstract
- Direct coupling or transformation of inert alkanes based on the selective C-H activation is of great importance for both chemistry and chemical engineering. Here, we report the coupling of polyenes that are transformed from n-dotriacontane (n-C32H66) through on-surface cascade dehydrogenation on Cu (110) surface, leading to the formation of polyacetylene (PA). Three distinct linkages have been resolved by scanning tunneling microscope (STM) and noncontact atomic force microscope (nc-AFM). Apart from the alpha-type linkage which is the stemless coupling of the terminal C-C double bond in trans-configuration, beta- and gamma-type linkages appear as knots or defects which are, in fact, the C-C couplings in cis-configurations. Interestingly, the "defects" can be effectively suppressed by adjusting the surface coverage, thus making it of general interest for uniform structure modulation.
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| 5. |
- Peng, Ningxin, et al.
(författare)
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Platelet mitochondrial DNA methylation : A novel biomarker for myocardial infarction – A preliminary study
- 2023
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Ingår i: International Journal of Cardiology. - 0167-5273.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Platelet activation and thrombus formation play critical roles in the pathogenesis of myocardial infarction (MI). In addition to their role in energy production, platelet mitochondria also regulate cellular functions related to apoptosis, oxidative stress, and inflammation. Epigenetic modifications of platelet mitochondrial DNA (mtDNA) may influence platelet function and are believed to be an important factor in MI. Therefore, the aim of this study was to investigate the differences in platelet mtDNA methylation levels between MI patients and controls. Methods: The present study utilized propensity score matching to generate 45 multivariate matched apparently healthy controls for 45 patients with newly-onset acute MI. Platelet mtDNA methylation levels were assessed through bisulfite-PCR pyrosequencing and compared between the two groups, with further adjustments made in the sensitivity analysis. Results: Among the measured mitochondrial genes (MT-COX1, MT-COX2, MT-COX3, MT-ND5, MT-ATP6 and tRNA_Leu), patients with MI exhibited statistically significant differences in mtDNA methylation levels as compared to matched controls. Specifically, higher levels of mtDNA methylation were observed in MT-COX1, MT-COX3, and tRNA_Leu, while a lower level was observed in MT-ATP6 (all p < 0.0001). These results remained robust in the sensitivity analysis. Conclusion: Our study demonstrated significant variations in platelet mtDNA methylation levels between patients with MI and controls. Platelet mtDNA methylation may serve as a novel biomarker for MI. This observation also provided some insights into the etiology of MI.
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| 6. |
- Wang, Sainan, et al.
(författare)
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Second-line antituberculosis drug exposure thresholds predictive of adverse events in multidrug-resistant tuberculosis treatment
- 2024
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Ingår i: International Journal of Infectious Diseases. - : ELSEVIER SCI LTD. - 1201-9712 .- 1878-3511. ; 140, s. 62-69
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study aimed to investigate the association between drug exposure and adverse events (AEs) during the standardized multidrug-resistant tuberculosis (MDR -TB) treatment, as well as to identify predictive drug exposure thresholds. Methods: We conducted a prospective, observational multicenter study among participants receiving standardized MDR -TB treatment between 2016 and 2019 in China. AEs were monitored throughout the treatment and their relationships to drug exposure (e.g., the area under the drug concentration -time curve from 0 to 24 h, AUC0-24 h ) were analyzed. The thresholds of pharmacokinetic predictors of observed AEs were identified by boosted classification and regression tree (CART) and further evaluated by external validation. Results: Of 197 study participants, 124 (62.9%) had at least one AE, and 15 (7.6%) experienced serious AEs. The association between drug exposure and AEs was observed including bedaquiline, its metabolite M2, moxifloxacin and QTcF prolongation (QTcF > 450 ms), linezolid and mitochondrial toxicity, cycloserine and psychiatric AEs. The CART -derived thresholds of AUC0-24 h predictive of the respective AEs were 3.2 mg <middle dot>h/l (bedaquiline M2); 49.3 mg <middle dot>h/l (moxifloxacin); 119.3 mg <middle dot>h/l (linezolid); 718.7 mg <middle dot>h/l (cycloserine). Conclusions: This study demonstrated the drug exposure thresholds predictive of AEs for key drugs against MDR -TB treatment. Using the derived thresholds will provide the knowledge base for further randomized clinical trials of dose adjustment to minimize the risk of AEs.
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| 7. |
- Ainsworth, Richard I, et al.
(författare)
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Systems-biology analysis of rheumatoid arthritis fibroblast-like synoviocytes implicates cell line-specific transcription factor function.
- 2022
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Rheumatoid arthritis (RA) is an immune-mediated disease affecting diarthrodial joints that remains an unmet medical need despite improved therapy. This limitation likely reflects the diversity of pathogenic pathways in RA, with individual patients demonstrating variable responses to targeted therapies. Better understanding of RA pathogenesis would be aided by a more complete characterization of the disease. To tackle this challenge, we develop and apply a systems biology approach to identify important transcription factors (TFs) in individual RA fibroblast-like synoviocyte (FLS) cell lines by integrating transcriptomic and epigenomic information. Based on the relative importance of the identified TFs, we stratify the RA FLS cell lines into two subtypes with distinct phenotypes and predicted activepathways. We biologically validate these predictions for the top subtype-specific TF RARα and demonstrate differential regulation of TGFβ signaling in the two subtypes. This study characterizes clusters of RA cell lines with distinctive TF biology by integrating transcriptomic and epigenomic data, which could pave the way towards a greater understanding of disease heterogeneity.
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| 8. |
- Cheng, Qiaoyun, et al.
(författare)
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The conversion of nanocellulose into solvent-free nanoscale liquid crystals by attaching long side-arms for multi-responsive optical materials
- 2020
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 8:32, s. 11022-11031
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Tidskriftsartikel (refereegranskat)abstract
- Nanocellulose, with its unique optical and chemical properties, has received increasing attention as feedstock to fabricate sustainable materials. However, achieving a nanocellulose-based solvent-free liquid crystal with good responsiveness still remains a challenge. Herein, for the first time, solvent-free supramolecular liquid crystals were fabricated by attaching long side-arms on the fiber-like nanocellulose derived from tunicate (TCNC) with an average width of 20 nm and 400-3000 nm in length. The side-arms were grafted via surface condensation with a charged organosilane, followed by further functionalization with a counter-ion polyoxyethylene ether. The nanoscale liquid crystals consisted of the stiff TCNC as the core and flexible side-arms as the soft shells, forming the core-shell structure with an average width of 34-36 nm. The resulting solvent-free liquid crystal exhibited transparent and viscous liquid-like fluidity, as well as a bright birefringence between the crossed polarizers at room temperature. In our findings, the stiff core provided crystal-like ordering, whereas the soft shells induced the high mobility of the TCNCs as a result of the increased fractional free volume, as shown by positron annihilation lifetime spectra. The unique flowability enables the possibility of multi-responsiveness to temperature, deformation, and alternating electric fields. In addition, the thermo-responsiveness can be regulated by tailoring the canopy. This work provides a novel strategy for the conversion of solid nanocellulose into a solvent-free nanoscale liquid crystal, which is promising for use as a responsive optical material.
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| 9. |
- d'Alessandro, Elisa, et al.
(författare)
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Thrombo-Inflammation in Cardiovascular Disease : An Expert Consensus Document from the Third Maastricht Consensus Conference on Thrombosis
- 2020
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Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 120:4, s. 538-564
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Tidskriftsartikel (refereegranskat)abstract
- Thrombo-inflammation describes the complex interplay between blood coagulation and inflammation that plays a critical role in cardiovascular diseases. The third Maastricht Consensus Conference on Thrombosis assembled basic, translational, and clinical scientists to discuss the origin and potential consequences of thrombo-inflammation in the etiology, diagnostics, and management of patients with cardiovascular disease, including myocardial infarction, stroke, and peripheral artery disease. This article presents a state-of-the-art reflection of expert opinions and consensus recommendations regarding the following topics: (1) challenges of the endothelial cell barrier; (2) circulating cells and thrombo-inflammation, focused on platelets, neutrophils, and neutrophil extracellular traps; (3) procoagulant mechanisms; (4) arterial vascular changes in atherogenesis; attenuating atherosclerosis and ischemia/reperfusion injury; (5) management of patients with arterial vascular disease; and (6) pathogenesis of venous thrombosis and late consequences of venous thromboembolism.
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| 10. |
- Fiore, Achille, et al.
(författare)
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Detailed spectrophotometric analysis of the superluminous and fast evolving SN 2019neq
- 2024
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Ingår i: Monthly notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 527:3, s. 6473-6494
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Tidskriftsartikel (refereegranskat)abstract
- SN 2019neq was a very fast evolving superluminous supernova. At a redshift z = 0.1059, its peak absolute magnitude was −21.5 ± 0.2 mag in g band. In this work, we present data and analysis from an extensive spectrophotometric follow-up campaign using multiple observational facilities. Thanks to a nebular spectrum of SN 2019neq, we investigated some of the properties of the host galaxy at the location of SN 2019neq and found that its metallicity and specific star formation rate are in a good agreement with those usually measured for SLSNe-I hosts. We then discuss the plausibility of the magnetar and the circumstellar interaction scenarios to explain the observed light curves, and interpret a nebular spectrum of SN 2019neq using published SUMO radiative-transfer models. The results of our analysis suggest that the spin-down radiation of a millisecond magnetar with a magnetic field B ≃ 6×1014 G could boost the luminosity of SN 2019neq.
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