Nanofluidic devices for the separation of biomolecules.

Over the last 30-years, microchip electrophoresis and its applications have expanded due to the benefits it offers. Nanochip electrophoresis, on the other hand, is viewed as an evolving area of electrophoresis because it offers some unique advantages not associated with microchip electrophoresis. These advantages arise from unique phenomena that occur in the nanometer domain not readily apparent in the microscale domain due to scale-dependent effects.

The role of R&D and economic policy uncertainty in Sri Lanka's economic growth.

In this paper, we assess the role of investment in research and development (R&D) and economic policy uncertainty (EPU) in Sri Lanka's economic growth experience. We do this by first determining which endogenous growth theories best explain the evolution of total factor productivity (TFP) in the country. Using historical time series data (1980-2018), we find that semi-endogenous growth theories best explain the evolution of TFP in Sri Lanka.

Label-Free Identification of Single Mononucleotides by Nanoscale Electrophoresis.

Nanoscale electrophoresis allows for unique separations of single molecules, such as DNA/RNA nucleobases, and thus has the potential to be used as single molecular sensors for exonuclease sequencing. For this to be envisioned, label-free detection of the nucleotides to determine their electrophoretic mobility (i.e.

Solid-phase XRN1 reactions for RNA cleavage: application in single-molecule sequencing.

Modifications in RNA are numerous (∼170) and in higher numbers compared to DNA (∼5) making the ability to sequence an RNA molecule to identify these modifications highly tenuous using next generation sequencing (NGS). The ability to immobilize an exoribonuclease enzyme, such as XRN1, to a solid support while maintaining its activity and capability to cleave both the canonical and modified ribonucleotides from an intact RNA molecule can be a viable approach for single-molecule RNA sequencing. In this study, we report an enzymatic reactor consisting of covalently attached XRN1 to a solid support as the groundwork for a novel RNA exosequencing technique.

Electrokinetic identification of ribonucleotide monophosphates (rNMPs) using thermoplastic nanochannels.

With advances in the design and fabrication of nanofluidic devices during the last decade, there have been a few reports on nucleic acid analysis using nanoscale electrophoresis. The attractive nature of nanofluidics is the unique phenomena associated with this length scale that are not observed using microchip electrophoresis. Many of these effects are surface-related and include electrostatics, surface roughness, van der Waals interactions, hydrogen bonding, and the electric double layer.

Open-tubular nanoelectrochromatography (OT-NEC): gel-free separation of single stranded DNAs (ssDNAs) in thermoplastic nanochannels.

Electrophoresis or electrochromatography carried out in nanometer columns (width and depth) offers some attractive benefits compared to microscale columns. These advantages include unique separation mechanisms that are scale dependent, fast separation times, and simpler workflow due to the lack of a need for column packing and/or wall coatings to create a stationary phase. We report the use of thermoplastics, in this case PMMA, as the substrate for separating single-stranded DNAs (ssDNAs).

Electrokinetic transport properties of deoxynucleotide monophosphates (dNMPs) through thermoplastic nanochannels.

The electrokinetic behavior of molecules in nanochannels (<100 nm in length) have generated interest due to the unique transport properties observed that are not seen in microscale channels. These nanoscale dependent transport properties include transverse electromigration arising from partial electrical double layer overlap, enhanced solute/wall interactions due to the small channel diameter, and field-dependent intermittent motion produced by surface roughness. In this study, the electrokinetic transport properties of deoxynucleotide monophosphates (dNMPs) were investigated, including the effects of electric field strength, surface effects, and composition of the carrier electrolyte (ionic concentration and pH).

Low PAPP-A: what are the clinical implications?

Ultrasound and pulsed Doppler can assist in confirming impaired placentation looking at fetal biometry and umbilical artery Dopplers. The authors recommend confirmation of fetal wellbeing at 28-30 weeks with a PAPP-A level below the first centile.