| 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. |
- Kumar, Ajith, et al.
(författare)
-
Flow control using hot splitter plates in the wake of a circular cylinder: A hybrid strategy
- 2024
-
Ingår i: Physics of fluids. - : AIP Publishing. - 1070-6631 .- 1089-7666. ; 36:1
-
Tidskriftsartikel (refereegranskat)abstract
- A novel and effective hybrid technique, which involves active surface heating strategies in conjunction with the use of passive splitter plates in the wake of the cylinder, is proposed. In this report, we present the results of a numerical investigation on the two-dimensional, laminar mixed convection flow over a circular cylinder with a hot rigid splitter plate attached to it on the wake side. A projection algorithm-based finite volume method is employed to obtain the solution of the coupled, nonlinear governing partial differential equations subjected to Courant–Friedrichs–Lewy conditions. The isothermal heating of the splitter plate under the influence of the gravity field generates an upward buoyancy force in the wake of the cylinder. For different length-to-diameter (L/D) ratios, the effect of heating on aerodynamic, wake, and heat transfer characteristics has been studied for a wide range of parameters; 75 ≤ Re ≤ 150, 0 ≤ Ri ≤ 1, and 0.5 ≤ L/D ≤ 1 at Pr = 0.7. It is observed that the hot splitter plate would bring about conspicuous changes such as asymmetry in the vortex shedding behind the cylinder at low Reynolds numbers. The outcomes demonstrate a notable improvement in convective heat transfer and drag, with gains of up to 7% and 15%, respectively. It is found that the rate of heat transfer and vortex shedding frequency decrease with an increase in L/D ratio. Correlations for the estimation of Strouhal number and Nusselt number have also been proposed which helps provide a more thorough understanding of thermal and aerodynamic features of the hybrid approach.
|
|
| 3. |
- Paidikondala, Maruthibabu, 1985-, et al.
(författare)
-
An Unexpected Role of Hyaluronic Acid in Trafficking siRNA Across the Cellular Barrier : The First Biomimetic, Anionic, Non-Viral Transfection Method
- 2019
-
Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 58:9, s. 2815-2819
-
Tidskriftsartikel (refereegranskat)abstract
- Circulating nucleic acids, such as short interfering RNA (siRNA), regulate many biological processes; however, the mechanism by which these molecules enter the cell is poorly understood. The role of extracellular-matrix-derived polymers in binding siRNAs and trafficking them across the plasma membrane is reported. Thermal melting, dynamic light scattering, scanning electron microscopy, and computational analysis indicate that hyaluronic acid can stabilize siRNA via hydrogen bonding and Van der Waals interactions. This stabilization facilitated HA size- and concentration-dependent gene silencing in a CD44-positive human osteosarcoma cell line (MG-63) and in human mesenchymal stromal cells (hMSCs). This native HA-based siRNA transfection represents the first report on an anionic, non-viral delivery method that resulted in approximately 60% gene knockdown in both cell types tested, which correlated with a reduction in translation levels.
|
|
| 4. |
|
|
| 5. |
- Samanta, Sumanta, et al.
(författare)
-
Heparin-Derived Theranostic Nanoprobes Overcome the Blood-Brain Barrier and Target Glioma in Murine Model
- 2022
-
Ingår i: Advanced Therapeutics. - : John Wiley & Sons. - 2366-3987. ; 5:6
-
Tidskriftsartikel (refereegranskat)abstract
- The poor permeability of theranostic agents across the blood-brain barrier (BBB) significantly hampers the development of new treatment modalities for neurological diseases. A new biomimetic nanocarrier is discovered using heparin (HP) that effectively passes the BBB and targets glioblastoma. Specifically, HP-coated gold nanoparticles (HP-AuNPs) are designed that are labeled with three different imaging modalities namely, fluorescein (FITC-HP-AuNP), radioisotope (68)Gallium (Ga-68-HP-AuNPs), and MRI active gadolinium (Gd-HP-AuNPs). The systemic infusion of FITC-HP-AuNPs in three different mouse strains (C57BL/6JRj, FVB, and NMRI-nude) displays excellent penetration and reveals uniform distribution of fluorescent particles in the brain parenchyma (69-86%) with some accumulation in neurons (8-18%) and microglia (4-10%). Tail-vein administration of radiolabeled Ga-68-HP-AuNPs in healthy rats also show Ga-68-HP-AuNP inside the brain parenchyma and in areas containing cerebrospinal fluid, such as the lateral ventricles, the cerebellum, and brain stem. Finally, tail-vein administration of Gd-HP-AuNPs (that displays approximate to threefold higher relaxivity than that of commercial Gd-DTPA) in an orthotopic glioblastoma (U87MG xenograft) model in nude mice demonstrates enrichment of T1-contrast at the intracranial tumor with a gradual increase in the contrast in the tumor region between 1 and 3 h. It is believed, the finding offers the untapped potential of HP-derived-NPs to deliver cargo molecules for treating neurological disorders.
|
|
