| 1. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)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. |
- Lin, Jiuluan, et al.
(author)
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Novel Method to Identify the Precentral Gyrus and Its Detailed Functional Distribution in Real Brain Surfaces Using Reconstructed 3D Brain Surface Imaging
- 2015
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In: JOURNAL OF MEDICAL IMAGING AND HEALTH INFORMATICS. - : American Scientific Publishers. - 2156-7018 .- 2156-7026. ; 5:2, s. 216-222
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Journal article (peer-reviewed)abstract
- Objective: To study the use of reconstructed 3D brain surface imaging (RBSI) to identify the precentral gyrus and its detailed functional distribution in epileptic patients. Method: A total of 12 refractory epilepsy cases that need intracranial electrode implantation were studied. In these patients, pre-operative magnetic resonance imaging (MRI) and functional MRI (fMRI) were conducted, and a cranial computed tomography (CT) scan was performed after electrode implantation. The RBSI was accomplished using Brain Voyager software based on MRI data, and then the 3D brain surface was integrated with the subdural electrode CT scan. The precentral gyrus was found in the reconstructed brain surface imaging according to their anatomical shape, and then were identified in the surgical field by comparing the exposed gyrus in the RBSI with the help of intraoperative photographs. Results: Total 12 cases of precentral gyrus was found and marked in the RBSI. There were 101 electrodes covering the precentral gyrus and 73 (72%) of them had motor response to electrical stimulation. In the contrast, (the area which is 1 cm ahead of the precentral gyrus), the motor response rate was 13% (17/130) (p < 0.05). During fMRI, 100% of the precentral gyrus and 58% (7/12) of post central gyrus was activated during hand movement. Whereas, no activation of the areas ahead of precentral gyrus was seen showing a significant difference between precentral gyrus and gyrus ahead. Conclusion: Our results demonstrated that using RBSI technique, it is possible to identify the precentral gyrus with precision.
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| 3. |
- Wang, Mengmeng, et al.
(author)
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Statistical analysis of whistler precursors upstream of foreshock transient shocks : MMS observations
- 2024
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In: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 51:8
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Journal article (peer-reviewed)abstract
- Using the high-time-resolution data from the Magnetospheric Multiscale mission, precursor waves upstream of foreshock transient (FT) shocks are statistically investigated using the four-spacecraft timing method. The wave frequencies and wave vectors determined in the plasma rest frame (PRF) are shown to follow the cold plasma dispersion relation for whistler waves. Combining with the feature of the right-hand polarization in the PRF, the precursors are identified as whistler-mode waves around the lower hybrid frequency. The occurrence of whistler precursors is independent of the Alfvén Mach number and the FT shock normal angle. More importantly, all the whistler precursors have group velocities pointing upstream in the shock frame, suggesting the dispersive radiation to be a possible generation mechanism. The study improves the understanding of not only the whistler precursors but also the overall FT shock dynamics.
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| 4. |
- Ke, Yuqi, et al.
(author)
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beta-Cyclodextrin-derived Room Temperature Macromolecular Ionic Liquids by PEGylated Anions
- 2020
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In: Macromolecular rapid communications. - : Wiley. - 1022-1336 .- 1521-3927. ; 41:8
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Journal article (peer-reviewed)abstract
- A series of cyclodextrin-derived room temperature macromolecular ionic liquids carrying rather low glass transition temperatures of -20 to -40 degrees C are synthesized via sequential esterification, quaternization, and anion metathesis reactions. In addition to being ionic in nature, they are viscous liquids at room temperature with more fluidic behavior at elevated temperatures. They serve as a solvent for organic dyes or iodine separation via a liquid-liquid extraction approach. This strategy is useful for the development of various sugar (macro)molecule-based functional ionic liquids as well as macromolecular ionic liquids.
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