| 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. |
- Huang, Yue, et al.
(författare)
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Memory Effect of Metal-Oxide-Silicon Capacitors with Self-Assembly Double-Layer Au Nanocrystals Embedded in Atomic-Layer-Deposited HfO2 Dielectric
- 2009
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Ingår i: Chinese Physics Letters. - 0256-307X .- 1741-3540. ; 26:10
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Tidskriftsartikel (refereegranskat)abstract
- We report the chemical self-assembly growth of Au nanocrystals on atomic-layer-deposited HfO2 films aminosilanized by (3-Aminopropyl)-trimethoxysilane aforehand for memory applications. The resulting Au nanocrystals show a density of about 4 x 10(11) cm(-2) and a diameter range of 5-8 nm. The metal-oxide-silicon capacitor with double-layer Au nanocrystals embedded in HfO2 dielectric exhibits a large C - V hysteresis window of 11.9 V for +/- 11 V gate voltage sweeps at 1 MHz, a flat-band voltage shift of 1.5 V after the electrical stress under 7 V for 1 ms, a leakage current density of 2.9 x 10(-8) A/cm(-2) at 9 V and room temperature. Compared to single-layer Au nanocrystals, the double-layer Au nanocrystals increase the hysteresis window significantly, and the underlying mechanism is thus discussed.
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| 3. |
- Liao, Zhong-Wei, et al.
(författare)
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Robust Low Voltage Program-Erasable Cobalt-Nanocrystal Memory Capacitors with Multistacked Al2O3/HfO2/Al2O3 Tunnel Barrier
- 2009
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Ingår i: Chinese Physics Letters. - 0256-307X .- 1741-3540. ; 26:8, s. 087303-
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Tidskriftsartikel (refereegranskat)abstract
- An atomic-layer-deposited Al2O3/HfO2/Al2O3 (A/H/A) tunnel barrier is investigated for Co nanocrystal memory capacitors. Compared to a single Al2O3 tunnel barrier, the A/H/A barrier can significantly increase the hysteresis window, i. e., an increase by 9V for +/- 12V sweep range. This is attributed to a marked decrease in the energy barriers of charge injections for the A/H/A tunnel barrier. Further, the Co-nanocrystal memory capacitor with the A/H/A tunnel barrier exhibits a memory window as large as 4.1V for 100 mu s program/erase at a low voltage of +/- 7V, which is due to fast charge injection rates, i. e., about 2.4 x 10(16) cm(-2) s(-1) for electrons and 1.9 x 10(16) cm(-2) s(-1) for holes.
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