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Vortical jet flows in the Reynolds number (Re) range from 1000 to 3425 and swirl number (S) below 0.5, alone and in combination with suction through a small aperture, are experimentally investigated using optical visualization. Schlieren photography is employed to assess the vortical flow structure and establish the fundamental understanding of the source-to-sink gas-dynamic coupling, including the role played by the flow rate, jet diameter, and separation distance between the gas jet source and the suction sink. Compared to vortex-free jets, vortical jets for Re > 2700 with swirl number S > 0.27 experience earlier laminar-to-turbulent transition, resulting in a rapid growth of the jet boundary. The ability to control the growth of the jet expansion and mass and momentum dissipation into the surrounding is demonstrated via the use of a coaxially aligned flow suction placed in the path of a jet. When a swirling jet is completely coupled with a flow suction, jet expansion is significantly suppressed. The suction/sink flow rate imposes a limit on the maximum input/source flow rate of the gas jet to achieve complete coupling. Furthermore, there is a maximum distance over which effective coupling can occur, and for all Reynolds numbers considered, this distance is shorter than the distance at which the jet structure breaks up into turbulent eddies in the absence of a sink. [ABSTRACT FROM AUTHOR]

We describe the DRILL (dry ion localization and locomotion) device, which is an interface for electrospray ionization (ESI)-mass spectrometry (MS) that exploits a swirling flow to enable the use of inertial separation to prescribe different fates for electrosprayed droplets based on their size. This source adds a new approach to charged droplet trajectory manipulation which, when combined with hydrodynamic drag forces and electric field forces, provides a rich range of possible DRILL operational modes. Here, we experimentally demonstrate sensitivity improvement obtained via vortex-induced inertial sorting of electrosprayed droplets/ions: one possible mode of DRILL operation. In this mode, DRILL removes larger droplets while accelerating the remainder of the ESI plume, producing a high velocity stream of gas-enriched spray with small, highly charged droplets and ions and directing it toward the MS inlet. The improved signal-to-noise ratio (10-fold enhancement) in the detection of angiotensin I is demonstrated using the DRILL interface coupled to ESI-MS along with an improved limit of detection (10-fold enhancement, 100 picomole) in the detection of angiotensin II. The utility of DRILL has also been demonstrated by liquid chromatography (LC)-MS: a stable isotope labeled peptide cocktail was spiked into a complex native tissue extract and quantified by unscheduled multiple reaction monitoring on a TSQ Vantage. DRILL demonstrated improved signal strength (up to a 700-fold) for 8 out of 9 peptides and had no effects on the peak shape of the transitions. [ABSTRACT FROM AUTHOR]

We describe the use of the fluorescent reporter compound CDr10b to label mid-intestinal structures in zebrafish larvae after simple immersion. CDr10b is deposited into the gut where it initially fills the lumen and is excreted. Using laser-mediated injury of the intestine, we show that CDr10b provides a useful readout of the integrity and repair of the epithelial cell barrier. In addition, CDr10b specifically labels the absorptive mid-intestine segment that is analogous to the mammalian small intestine. By perturbing retinoic acid signaling, which regulates the size of the mid-intestine segment, we show that CDr10b is a valuable tool to rapidly assess developmental malformations of the intestine in live animals. [ABSTRACT FROM AUTHOR]

RNA processing defects in chloroplasts were previously associated with increased plasmodesmata (PD) permeability. However, the underlying mechanisms for such association are still unknown. To provide insight into this, we silenced the expression of chloroplast-located INCREASED SIZE EXCLUSION LIMIT 2 (ISE2) RNA helicase in Nicotiana benthamiana leaves and determined an increase in PD permeability which is caused by a reduction of PD callose deposition. Moreover, the silencing of two other nuclear genes encoding chloroplastic enzymes involved in RNA processing, RH3 , and CLPR2, also increased PD permeability accompanied by reduced callose accumulation at PD. In addition, we quantified the plastidic hydrogen peroxide levels using the chloroplast-targeted fluorescent sensor, HyPer, in ISE2 , RH3, and CLPR2 silenced N. benthamiana leaves. The levels of chloroplastic hydrogen peroxide were not correlated with the increased cell-to-cell movement of the marker protein GFP2X. We, therefore, propose that defects in chloroplast RNA metabolism mediate PD gating by suppressing PD callose deposition, and hydrogen peroxide levels in the organelles are not directly linked to this process. • The VIGS silencing of ISE2, RH3 and CLPR2 (nuclear-encoded chloroplastic-targeted genes directly and indirectly involved in RNA processing) increases the intercellular propagation via plasmodesmata (PD) of GFP2X but not GFP1X in N. benthamiana leaves. • Reduced callose accumulation at individual PD-pit fields revealed by aniline blue staining explained the increased PD permeability observed in N. benthamiana. • Hydrogen peroxide accumulation in chloroplasts revealed by HyPer did not show a correlation to the increased PD permeability. [ABSTRACT FROM AUTHOR]

Histone deacetylase 2 ( HDAC2) is aberrantly regulated and plays a pivotal role in the development of hepatocellular carcinoma ( HCC) through regulation of cell-cycle components at the transcriptional level, but the underlying mechanism leading to oncogenic HDAC2 remains unknown. In this study, we show that expression of CK2α (casein kinase II α subunit) was up-regulated in a large cohort of human HCC patients, and that high expression of CK2α was significantly associated with poor prognosis of HCC patients in terms of five-year overall survival. It was also found that CK2α over-expression positively correlated with HDAC2 over-expression in a subset of HCCs. We observed that treatment with epidermal growth factor ( EGF) elicited an increase in CK2α expression and Akt phosphorylation, causing induction of HDAC2 expression in liver cancer cells. It was also observed that ectopic expression of dominant-negative CK2α blocked EGF-induced HDAC2 expression, and that ectopic CK2α expression attenuated the suppressive effect of Akt knockdown on HDAC2 expression in liver cancer cells. Targeted disruption of CK2α influenced the cell cycle, causing a significant increase in the number of liver cancer cells remaining in G2/M phase, and suppressed growth via repression of Cdc25c and cyclin B in liver cancer cells. Taken together, our findings suggest the oncogenic potential of CK2α in liver tumorigenesis. Furthermore, a regulatory mechanism for HDAC2 expression is proposed whereby EGF induces transcriptional activation of HDAC2 by CK2α/Akt activation in liver cancer cells. Therefore, this makes CK2α a promising target in cancer therapy. [ABSTRACT FROM AUTHOR]