| 1. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
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.
|
|
| 2. |
- Enright, Michael J., et al.
(författare)
-
Role of Atomic Structure on Exciton Dynamics and Photoluminescence in NIR Emissive InAs/InP/ZnSe Quantum Dots
- 2022
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 126:17, s. 7576-7587
-
Tidskriftsartikel (refereegranskat)abstract
- The development of bright, near-infrared-emissive quantum dots (QDs) is a necessary requirement for the realization of important new classes of technology. Specifically, there exist significant needs for brighter, heavy metal-free, near-infrared (NIR) QDs for applications with high radiative efficiency that span diverse applications, including down-conversion emitters for high-performance luminescent solar concentrators. We use a combination of theoretical and experimental approaches to synthesize bright, NIR luminescent InAs/InP/ZnSe QDs and elucidate fundamental material attributes that remain obstacles for development of near-unity NIR QD luminophores. First, using Monte Carlo ray tracing, we identify the atomic and electronic structural attributes of InAs core/shell, NIR emitters, whose luminescence properties can be tailored by synthetic design to match most beneficially those of high-performance, single-band-gap photovoltaic devices based on important semiconductor materials, such Si or GaAs. Second, we synthesize InAs/InP/ZnSe QDs based on the optical attributes found to maximize LSC performance and develop methods to improve the emissive qualities of NIR emitters with large, tunable Stokes ratios, narrow emission linewidths, and high luminescence quantum yields (here reaching 60 +/- 2%). Third, we employ atomistic electronic structure calculations to explore charge carrier behavior at the nanoscale affected by interfacial atomic structures and find that significant exciton occupation of the InP shell occurs in most cases despite the InAs/InP type I bulk band alignment. Furthermore, the density of the valence band maximum state extends anisotropically through the (111) crystal planes to the terminal InP surfaces/interfaces, indicating that surface defects, such as unpassivated phosphorus dangling bonds, located on the (111) facets play an outsized role in disrupting the valence band maximum and quenching photoluminescence.
|
|
| 3. |
- Hannan, Katherine M., et al.
(författare)
-
Nuclear stabilization of p53 requires a functional nucleolar surveillance pathway
- 2022
-
Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 41:5
-
Tidskriftsartikel (refereegranskat)abstract
- The nucleolar surveillance pathway monitors nucleolar integrity and responds to nucleolar stress by mediating binding of ribosomal proteins to MDM2, resulting in p53 accumulation. Inappropriate pathway activation is implicated in the pathogenesis of ribosomopathies, while drugs selectively activating the pathway are in trials for cancer. Despite this, the molecular mechanism(s) regulating this process are poorly understood. Using genome-wide loss-of-function screens, we demonstrate the ribosome biogenesis axis as the most potent class of genes whose disruption stabilizes p53. Mechanistically, we identify genes critical for regulation of this pathway, including HEATR3. By selectively disabling the nucleolar surveillance pathway, we demonstrate that it is essential for the ability of all nuclear-acting stresses, including DNA damage, to induce p53 accumulation. Our data support a paradigm whereby the nucleolar surveillance pathway is the central integrator of stresses that regulate nuclear p53 abundance, ensuring that ribosome biogenesis is hardwired to cellular proliferative capacity.
|
|
| 4. |
- Schuermans, Art, et al.
(författare)
-
Clonal haematopoiesis of indeterminate potential predicts incident cardiac arrhythmias
- 2024
-
Ingår i: European Heart Journal. - 0195-668X. ; 45:10, s. 791-805
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Clonal haematopoiesis of indeterminate potential (CHIP), the age-related expansion of blood cells with preleukemic mutaAims tions, is associated with atherosclerotic cardiovascular disease and heart failure. This study aimed to test the association of CHIP with new-onset arrhythmias.Methods UK Biobank participants without prevalent arrhythmias were included. Co-primary study outcomes were supraventricular arrhythmias, bradyarrhythmias, and ventricular arrhythmias. Secondary outcomes were cardiac arrest, atrial fibrillation, and any arrhythmia. Associations of any CHIP [variant allele fraction (VAF) ≥ 2%], large CHIP (VAF ≥10%), and gene-specific CHIP subtypes with incident arrhythmias were evaluated using multivariable-adjusted Cox regression. Associations of CHIP with myocardial interstitial fibrosis [T1 measured using cardiac magnetic resonance (CMR)] were also tested. Results This study included 410 702 participants [CHIP: n = 13 892 (3.4%); large CHIP: n = 9191 (2.2%)]. Any and large CHIP were associated with multi-variable-adjusted hazard ratios of 1.11 [95% confidence interval (CI) 1.04–1.18; P = .001] and 1.13 (95% CI 1.05–1.22; P = .001) for supraventricular arrhythmias, 1.09 (95% CI 1.01–1.19; P = .031) and 1.13 (95% CI 1.03–1.25; P = .011) for bradyarrhythmias, and 1.16 (95% CI, 1.00–1.34; P = .049) and 1.22 (95% CI 1.03–1.45; P = .021) for ventricular arrhythmias, respectively. Associations were independent of coronary artery disease and heart failure. Associations were also heterogeneous across arrhythmia subtypes and strongest for cardiac arrest. Gene-specific analyses revealed an increased risk of arrhythmias across driver genes other than DNMT3A. Large CHIP was associated with 1.31-fold odds (95% CI 1.07–1.59; P = .009) of being in the top quintile of myocardial fibrosis by CMR. Conclusions CHIP may represent a novel risk factor for incident arrhythmias, indicating a potential target for modulation towards arrhythmia prevention and treatment.
|
|
| 5. |
- Sun, Michelle T., et al.
(författare)
-
Meta-Analysis of Intraocular Bleeding With Dual Antiplatelet Therapy Using P2Y12 Inhibitors Prasugrel or Ticagrelor
- 2020
-
Ingår i: American Journal of Cardiology. - : EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC. - 0002-9149 .- 1879-1913. ; 125:8, s. 1280-1283
-
Forskningsöversikt (refereegranskat)abstract
- Intraocular bleeding is a devastating clinical event due to its potentially blinding nature. It is not known if determine if dual antiplatelet therapy using aspirin and potent P2Y12 inhibitors increases this risk. We searched MEDLINE and ClinicalTrials.gov for randomized controlled trials that were phase III, randomly assigned patients to dual antiplatelet therapy with either aspirin and a potent P2Y12 inhibitor or aspirin and clopidogrel, had follow-up of 6 months, and at least 200 patients. Corresponding authors were contacted for intraocular bleeding data. Inverse-variance, weighted, fixed-effects meta-analysis was undertaken, with random-effects meta-analysis performed as a sensitivity analysis. Four trials enrolling 42,850 patients were included. The median follow-up ranged from 12 to 14 months. There was overall low risk of bias. Pooled analysis demonstrated no statistically significant increase in the risk of intraocular bleeding with dual antiplatelet therapy using potent P2Y12 inhibitors compared with clopidogrel (risk ratio 0.89, 95% confidence interval 0.58 to 136). There was no significant heterogeneity observed across trials (I-2 statistic 0%, p = 0.98). The use of random-effects meta-analysis did not change the effect estimate or confidence intervals, and the results appeared similar when stratified by potent P2Y12 inhibitor (p = 0.97). In conclusion, this collaborative meta-analysis of dual antiplatelet trials does not suggest that the risk of intraocular bleeding is increased with the use of potent P2Y12 inhibitors compared with clopidogrel. Our results suggest that these potent P2Y12 inhibitors may continue to be used cautiously where indicated as part of dual antiplatelet therapy, even in those at high risk of spontaneous intraocular bleeding. Crown Copyright (C) 2020 Published by Elsevier Inc. All rights reserved.
|
|
