| 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. |
- Liu, Daosheng, et al.
(författare)
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Magnetic Properties and Vibration Characteristics of Amorphous Alloy Strip and Its Combination
- 2019
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Ingår i: IET Electric Power Applications. - : Institution of Engineering and Technology (IET). - 1751-8660 .- 1751-8679. ; 13:10, s. 1589-1597
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Tidskriftsartikel (refereegranskat)abstract
- Although the cores made with amorphous metal alloy have lowered no-load losses compared with the orientation silicon steel cores, a high cost and noise level are inevitable because the magnetostriction for amorphous metal alloy strip is larger than the ordinary one. This paper mainly focused on the experimental systems and methods for magnetic properties measurement, vibration characteristics and noise level of amorphous alloy strip and combinations. The vibration characteristics and noise level of amorphous alloy composite strip were also studied. The influence of annealing process on magnetic energy, vibration characteristics and noise level of amorphous alloy core were analyzed in detail as well. All the testing results and analysis above are helpful for the transformer manufacturers, and they can replace the expensive amorphous alloy metal strip with the combination ones to reduce the noise and the cost of the cores.
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| 3. |
- Menkveld, Albert J., et al.
(författare)
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Nonstandard Errors
- 2024
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Ingår i: JOURNAL OF FINANCE. - : Wiley-Blackwell. - 0022-1082 .- 1540-6261. ; 79:3, s. 2339-2390
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Tidskriftsartikel (refereegranskat)abstract
- In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty-nonstandard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for more reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants.
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| 4. |
- Cai, Liangliang, et al.
(författare)
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Direct Formation of C-C Double-Bonded Structural Motifs by On-Surface Dehalogenative Homocoupling of gem-Dibromomethyl Molecules
- 2018
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Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 12:8, s. 7959-7966
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Tidskriftsartikel (refereegranskat)abstract
- Conductive polymers are of great importance in a variety of chemistry-related disciplines and applications. The recently developed bottom-up on-surface synthesis strategy provides us with opportunities for the fabrication of various nanostructures in a flexible and facile manner, which could be investigated by high-resolution microscopic techniques in real space. Herein, we designed and synthesized molecular precursors functionalized with benzal gem-dibromomethyl groups. A combination of scanning tunneling microscopy, noncontact atomic force microscopy, high-resolution synchrotron radiation photoemission spectroscopy, and density functional theory calculations demonstrated that it is feasible to achieve the direct formation of C-C double-bonded structural motifs via on-surface dehalogenative homocoupling reactions on the Au(111) surface. Correspondingly, we convert the sp(3)-hybridized state to an sp(2)-hybridized state of carbon atoms, i.e., from an alkyl group to an alkenyl one. Moreover, by such a bottom-up strategy, we have successfully fabricated poly(phenylenevinylene) chains on the surface, which is anticipated to inspire further studies toward understanding the nature of conductive polymers at the atomic scale.
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| 5. |
- Liu, Jiacheng, et al.
(författare)
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Improvement in modeling NH3/CH4 combustion based on the effects of the H-abstraction reactions and disproportionation reactions
- 2024
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Ingår i: Journal of the Energy Institute. - 1743-9671. ; 114
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Tidskriftsartikel (refereegranskat)abstract
- The H-abstraction reactions and disproportionation reactions play very important roles in the NH3/CH4 combustion model. The rate coefficient of the H-abstraction reaction, CH2O + NH2[dbnd]HCO + NH3 (R1430), theoretically calculated by Li & Lü was multiplied by 100 in the works of Dai et al. to better match the experiment, which was repeatedly adopted in the subsequent NH3/CH4 kinetic models. Moreover, the disproportionation reaction, HCO + NH2[dbnd]CO + NH3 (R1449), is not considered in the current existing NH3/CH4 kinetic models. In this work, the NH3–CH4 model is proposed including the C1–C2 sub-model, NH3 sub-model, and cross-reactions between nitrogen-containing species and hydrocarbon species including R1430 with the rate coefficient of Li & Lü, and R1449. The NH3–CH4 model was extensively validated by the SPs, IDTs, and LFSs of NH3/CH4 mixtures from the literature. The effects of the H-abstraction reaction and disproportionation reactions on the profiles of CH2O, IDTs, and LFSs of NH3/CH4 are closely studied by the sensitivity analysis and the rate of production (ROP) analysis using the NH3–CH4 model, and the effects of R1430 and R1449 are discussed by the comparison among the NH3–CH4 model, KAUST model and KAUST model with original rate constants. R1430 inhibits the CH2O formation. Multiplying the rate constant of R1430 by 100 in the KAUST model significantly deteriorates the prediction of CH2O. R1449 has significant inhibiting effects on LFSs due to reducing the H production in the pathway HCO→CO in the NH3–CH4 model. The rate constant of R1430 had to be artificially enhanced to predict well LFSs of NH3/CH4 mixtures in the KAUST model due to the absence of R1449. R1430 has significant promoting effects on IDTs, and the disproportionation reactions have a negligible influence.
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| 6. |
- Park, Bumjun, et al.
(författare)
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Ion Coordination and Transport in Magnesium Polymer Electrolytes Based on Polyester-co-Polycarbonate
- 2021
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Ingår i: Energy Material Advances. - : American Association for the Advancement of Science (AAAS). - 2692-7640. ; 2021, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Magnesium-ion-conducting solid polymer electrolytes have been studied for rechargeable Mg metal batteries, one of the beyond-Li-ion systems. In this paper, magnesium polymer electrolytes with magnesium bis(trifluoromethane)sulfonimide (Mg(TFSI)2) salt in poly(ε-caprolactone-co-trimethylene carbonate) (PCL-PTMC) were investigated and compared with the poly(ethylene oxide) (PEO) analogs. Both thermal properties and vibrational spectroscopy indicated that the total ion conduction in the PEO electrolytes was dominated by the anion conduction due to strong polymer coordination with fully dissociated Mg2+. On the other hand, in PCL-PTMC electrolytes, there is relatively weaker polymer–cation coordination and increased anion–cation coordination. Sporadic Mg- and F-rich particles were observed on the Cu electrodes after polarization tests in Cu|Mg cells with PCL-PTMC electrolyte, suggesting that Mg was conducted in the ion complex form (MgxTFSIy) to the copper working electrode to be reduced which resulted in anion decomposition. However, the Mg metal deposition/stripping was not favorable with either Mg(TFSI)2 in PCL-PTMC or Mg(TFSI)2 in PEO, which inhibited quantitative analysis of magnesium conduction. A remaining challenge is thus to accurately assess transport numbers in these systems.
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| 7. |
- Wang, Fei, et al.
(författare)
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Endothelial cell heterogeneity and microglia regulons revealed by a pig cell landscape at single-cell level
- 2022
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Pigs are valuable large animal models for biomedical and genetic research, but insights into the tissue- and cell-type-specific transcriptome and heterogeneity remain limited. By leveraging single-cell RNA sequencing, we generate a multiple-organ single-cell transcriptomic map containing over 200,000 pig cells from 20 tissues/organs. We comprehensively characterize the heterogeneity of cells in tissues and identify 234 cell clusters, representing 58 major cell types. In-depth integrative analysis of endothelial cells reveals a high degree of heterogeneity. We identify several functionally distinct endothelial cell phenotypes, including an endothelial to mesenchymal transition subtype in adipose tissues. Intercellular communication analysis predicts tissue- and cell type-specific crosstalk between endothelial cells and other cell types through the VEGF, PDGF, TGF-beta, and BMP pathways. Regulon analysis of single-cell transcriptome of microglia in pig and 12 other species further identifies MEF2C as an evolutionally conserved regulon in the microglia. Our work describes the landscape of single-cell transcriptomes within diverse pig organs and identifies the heterogeneity of endothelial cells and evolutionally conserved regulon in microglia.
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