| 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. |
- Huang, Kun, et al.
(författare)
-
Effect of acidosis on adipose-derived stem cell impairment and gene expression
- 2024
-
Ingår i: Regenerative Therapy. - 2352-3204. ; 25, s. 331-343
-
Tidskriftsartikel (refereegranskat)abstract
- Based on disappointing results of stem cell-based application in clinical trials for patients with critical limb ischemia, we hypothesized that the acidic environment might be the key factor limiting cell survival and function. In the present study, we used microdialysis to determine presence of acidosis and metabolic imbalance in critical ischemia. Moreover, we explored the effect of extracellular acidosis on adipose-derived stem cells (ADSCs) at molecular and transcriptional level. Our data demonstrate that low pH negatively regulates cell proliferation and survival, also, it results in cell cycle arrest, mitochondrial dynamics disorder, DNA damage as well as the impairment of proangiogenic function in a pH-dependent manner. Further transcriptome profiling identified the pivotal signaling pathways and hub genes in response to acidosis. Collectively, these findings provide strong evidences for a critical role of acidosis in ADSCs impairment with ischemic condition and suggest treatments focus on tissue pH balance and acidosis-mediated hub genes may have therapeutic potential in stem cell-based application.
|
|
| 3. |
- Wang, Ji, et al.
(författare)
-
Microstructure investigations of Fe50Mn30Co10Cr10 dual-phase high-entropy alloy under Fe ions irradiation
- 2021
-
Ingår i: Journal of Nuclear Materials. - : ELSEVIER. - 0022-3115 .- 1873-4820. ; 552
-
Tidskriftsartikel (refereegranskat)abstract
- An Fe50Mn30Co10Cr10 dual-phase high-entropy alloy (DP-HEA) was irradiated at room temperature with 3 MeV Fe ions to a dose of 50 displacement per atom (dpa). Potentials of special elemental designed DP-HEAs with low stacking fault energy (SFE) as promising candidate materials for future nuclear energy systems are evaluated. Transmission electron microscopy (TEM) analysis finds that FCC gamma-gamma, HCP epsilon-epsilon twinning structures and FCC gamma-HCP epsilon co-existed structures of the DP-HEA, which correlate with the combined high strength and high ductility featured by this alloy, remain stable under a displacement damage of 50 dpa. No elemental segregation after irradiation was detected by energy dispersive spectroscopy. The results indicate that TWIP and TRIP mechanisms, owned by many other DP-HEAs, may still work effectively, and the materials still possess the merits of combined high strength and ductility brought by TWIP and TRIP mechanisms under irradiation conditions. Defects free channels (DFCs) and abundant Lomer-Cottrell (L-C) locks are observed in the irradiated samples after tensile deformation. The immobile L-C locks restrict DFCs growth, prevent the pile-up of dislocation along grain boundaries, thus sustaining dislocations in the grain interior. This study provides a new strategy to improve simultaneously the irradiation resistance and mechanical properties of structural materials by introducing the TWIP and TRIP mechanisms. (C) 2021 Elsevier B.V. All rights reserved.
|
|
