858 research outputs found
In Vitro Synergistic Antiviral Activity of Black Tea Theaflavins and Acyclovir on Herpes Simplex Virus Types 1 and 2 in A549 Cells
Herpes simplex virus (HSV) is responsible for one of the most common infections within the population. The primary antiviral used against HSV infections are nucleoside analog drugs such as acyclovir and its deviates. However, in recent years the number of cases of drug resistant HSV has increased, resulting in interest for new novel treatments. Promising antiviral agents are theaflavins found within black tea derived from Camellia sinensis. These theaflavins include theaflavin (TF1), theaflavin-3-monogallate (TF2A), theaflavin-3â-monogallate (TF2B), and theaflavin-3-3â-digallate (TF3). Previous studies have supported that theaflavins from black tea, specifically TF3, inhibit the process of viral absorption. Due to this mode of action, black tea theaflavins show potential for synergistic antiviral activity when combined with drugs such as acyclovir, which inhibit viral replication. This study examined the antiviral activity of black tea extract and TF3 with acyclovir on HSV-1 and HSV-2 infections in A549 cells. Cytotoxic analysis was performed with a trypan blue, WST-1 cell proliferation, and ToxGlo assay. Data for each assay supported that concentration of 100 ”M of TF3 or 100 ”M BTE in combination with 50 ”M of acyclovir produce no cytotoxicity in A549 cells. Antiviral activity was measured using a WST-1 based antiviral assay along with a viral ToxGlo assay. In each case theaflavins showed higher antiviral activity when combined with acyclovir, with up to 21.8% increase in viral inhibition. Moreover, the mixture showed higher antiviral activity than acyclovir alone at concentrations of 5 ”M. Furthermore, isolated TF3 with acyclovir showed higher levels of viral inhibition than the combination of theaflavins with acyclovir. In conclusion, acyclovir and black tea theaflavins, TF3 in particular, have shown synergistic activity and may provide an alternative regimen, to decrease emergence of resistant strains of HSV types 1 and 2
Where the granular flows bend
Based on IMaX/Sunrise data, we report on a previously undetected phenomenon
in solar granulation. We show that in a very narrow region separating granules
and intergranular lanes the spectral line width of the Fe I 5250.2 A line
becomes extremely small. We offer an explanation of this observation with the
help of magneto-convection simulations. These regions with extremely small line
widths correspond to the places where the granular flows bend from mainly
upflow in granules to downflow in intergranular lanes. We show that the
resolution and image stability achieved by IMaX/Sunrise are important
requisites to detect this interesting phenomenon.Comment: Accepted for the Sunrise Special Issue of ApJ
Detection of large acoustic energy flux in the solar atmosphere
We study the energy flux carried by acoustic waves excited by convective
motions at sub-photospheric levels. The analysis of high-resolution
spectropolarimetric data taken with IMaX/Sunrise provides a total energy flux
of ~ 6400--7700 Wm at a height of ~ 250 km in the 5.2-10 mHz range, i.e.
at least twice the largest energy flux found in previous works. Our estimate
lies within a factor of 2 of the energy flux needed to balance radiative losses
from the chromosphere according to Anderson & Athay (1989) and revives interest
in acoustic waves for transporting energy to the chromosphere. The acoustic
flux is mainly found in the intergranular lanes but also in small
rapidly-evolving granules and at the bright borders, forming dark dots and
lanes of splitting granules.Comment: Accepted on ApJ Letters as part of the special Sunrise issu
Der Schlaganfall : eine Herausforderung fĂŒr die klinische Forschung
Hinter dem Begriff "Schlaganfall" verbergen sich verschiedene Krankheitsbilder, die durch gemeinsame Merkmale gekennzeichnet sind: Die Beschwerden treten akut auf, oftmals von einer Sekunde zur anderen. Ein Schlagfall ist darĂŒber hinaus durch das Auftreten von charakteristischen neurologischen Symptomen gekennzeichnet, wie halbseitige LĂ€hmungen, Sprach-, Seh- oder GefĂŒhlsstörungen. Die Ursache hierfĂŒr liegt in VerĂ€nderungen in den BlutgefĂ€Ăen des Gehirns, wie die Autoren erlĂ€utern
Atmosphere-like turbulence generation with surface-etched phase-screens
We built and characterized an optical system that emulates the optical
characteristics of an 8m-class telescope like the Very Large Telescope. The
system contains rotating glass phase-screens to generate realistic
atmosphere-like optical turbulence, as needed for testing multi-conjugate
adaptive optics systems. In this paper we present an investigation of the
statistical properties of two phase-screens etched on glass-plate surfaces,
obtained from Silios Technologies. Those etched screens are highly transmissive
(above 85%) from 0.45 to 2.5 microns. From direct imaging, their Fried
parameter r0 values (0.43+-0.04 mm and 0.81+-0.03 mm, respectively, at 0.633
microns) agree with the expectation to within 10%. This is also confirmed by a
comparison of measured and expected Zernike coefficient variances. Overall, we
find that those screens are quite reproducible, allowing sub-millimetre r0
values, which were difficult to achieve in the past. We conclude that the
telescope emulator and phase-screens form a powerful atmospheric turbulence
generator allowing systematic testing of different kinds of AO instrumentation.Comment: 10 pages, 8 figures, 3 mpeg movies. Submitted to Optics Expres
Correlation analysis between the jet exhaust velocity field and microphone-array acoustic measurements for a turbo-fan engine
Simultaneous flow and acoustic measurements have been acquired for an aircraft, during ground operation. Measurements of velocity field data with stereoscopic particle image velocimetry (SPIV) on the engine-exhaust jet are correlated with the acoustic-pressure signals
of a 120 microphone linear array. The turbulent velocity and the applied-stress components of the Lighthill- and Lilley-analogy source terms in the SPIV region are correlated with the microphone array. Convection effects on the propagating sound waves are neglected in the
present study. The self-noise term in the Lighthill quadrupole, shows a hot spot for the correlation in the by-pass to ambient shear layer. This high correlation region is clearly visible in one of the analysed test points only, while in general a poor statistical convergence seems to affect the test-source correlation
Taming the germyliumylidene [CIGe:](+) and germathionium [CIGe=S](+) ions by donor-acceptor stabilization using 1,8-bis(tributylphosphazenyl)naphthalene
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugĂ€nglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The novel chlorogermyliumylidene complex L[ClGe:]+ (L = 1,8-bis(tri-n-butylphosphanzenyl)naphthalene) with a ânakedâ Clâ as a counter anion was synthesized through reaction of L with Cl2Ge: and fully characterized. Its reaction with elemental sulfur afforded the first germathionium [ClGe[double bond, length as m-dash]S]+ cation containing species. The latter has also been fully characterized, including single-crystal X-ray diffraction analysis
First high-resolution images of the Sun in the 2796 \AA{} Mg II k line
We present the first high-resolution solar images in the Mg II k 2796 \AA{}
line. The images, taken through a 4.8 \AA{} broad interference filter, were
obtained during the second science flight of SUNRISE in June 2013 by the SuFI
instrument. The Mg II k images display structures that look qualitatively very
similar to images taken in the core of Ca II H. The Mg II images exhibit
reversed granulation (or shock waves) in the internetwork regions of the quiet
Sun, at intensity contrasts that are similar to those found in Ca II H. Very
prominent in Mg II are bright points, both in the quiet Sun and in plage
regions, particularly near disk center. These are much brighter than at other
wavelengths sampled at similar resolution. Furthermore, Mg II k images also
show fibril structures associated with plage regions. Again, the fibrils are
similar to those seen in Ca II H images, but tend to be more pronounced,
particularly in weak plage.Comment: Accepted for publication in The Astrophysical Journal Letter
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