| 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. |
- Bost, Jeremy P., et al.
(författare)
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Novel endosomolytic compounds enable highly potent delivery of antisense oligonucleotides
- 2022
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- The therapeutic and research potentials of oligonucleotides (ONs) have been hampered in part by their inability to effectively escape endosomal compartments to reach their cytosolic and nuclear targets. Splice-switching ONs (SSOs) can be used with endosomolytic small molecule compounds to increase functional delivery. So far, development of these compounds has been hindered by a lack of high-resolution methods that can correlate SSO trafficking with SSO activity. Here we present in-depth characterization of two novel endosomolytic compounds by using a combination of microscopic and functional assays with high spatiotemporal resolution. This system allows the visualization of SSO trafficking, evaluation of endosomal membrane rupture, and quantitates SSO functional activity on a protein level in the presence of endosomolytic compounds. We confirm that the leakage of SSO into the cytosol occurs in parallel with the physical engorgement of LAMP1-positive late endosomes and lysosomes. We conclude that the new compounds interfere with SSO trafficking to the LAMP1-positive endosomal compartments while inducing endosomal membrane rupture and concurrent ON escape into the cytosol. The efficacy of these compounds advocates their use as novel, potent, and quick-acting transfection reagents for antisense ONs.
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| 3. |
- Minelli, Caterina, et al.
(författare)
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Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles
- 2022
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 14, s. 4690-4704
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Tidskriftsartikel (refereegranskat)abstract
- We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles.
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| 4. |
- Saxena, Shalini, et al.
(författare)
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Plasma-Induced Graft Polymerization of Acrylic Acid onto Poly(propylene) Monofilament : Characterization
- 2010
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Ingår i: Plasma Processes and Polymers. - : Wiley. - 1612-8850. ; 7:7, s. 610-618
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Tidskriftsartikel (refereegranskat)abstract
- Poly(propylene) (PP) filaments were functionalized by plasma-grafting of acrylic acid and the characterization of the grafted filaments was carried out using various techniques. XPS content which causes a decrease in the analysis showed an increase in the oxygenated contact angle decreased from 88 for virgin PP to 28 for the filament with the maximum graft level. The storage of the samples leads to the loss in hydrophilicity. The grafts do not lead to any crystalline changes in the filament structure; significant changes however occur on the surface of the filaments as a function of the degree of grafting.
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| 5. |
- Sharma, Silky, et al.
(författare)
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Application of Technology and Innovation in Fintech and it's adaptability in India
- 2022
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Ingår i: Proceedings of 2nd International Conference on Innovative Practices in Technology and Management, ICIPTM 2022. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665466431 ; , s. 305-311
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Konferensbidrag (refereegranskat)abstract
- India is a growing fintech market with a population of approximately 1.3 billion. The bankless and majority of the bankless population makes India an exciting global space for financial technology. Fintech is seen as a game changer and disruptive innovation that can rock traditional financial markets. Fintech has grown rapidly in India over the last five years and is expected to continue to grow in the near future. This article first focuses on the basic types of financial technology and its capabilities, and also discusses the opportunities and challenges faced in the Indian business environment. This research article basically extends FinTech's quantitative assessment of customer adaptability and qualitative analysis of technical, economic and demographic factors that may lead to FinTech's adaptability in India.
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