2,696 research outputs found
Evaluation of Diuretic Activity of Aqueous and Methanol Extracts of Lepidium sativum Garden Cress (Cruciferae) in Rats
Purpose: The present study was undertaken to investigate diuretic effect of aqueous and methanol extracts of the dried seeds of Lepidium sativum in normal rats.Method: Aqueous and methanol extracts of L. sativum seeds were administered to experimental rats orally at doses of 50 and 100 mg/kg p.o. Hydrochlorothiazide (10 mg/kg) was used as positive control instudy. The diuretic effect of the extracts was evaluated by measuring urine volume, sodium and potassium content, conductivity and pH.Result: Urine volume was significantly increased by the two doses of aqueous and methanol extracts in comparison to control group. While the excretion of sodium was also increased by both extracts, potassium excretion was only increased by the aqueous extract at a dose of 100 mg/kg. There was no significant change in the conductivity and pH of urine after administration of the L. sativum extracts. The diuretic effect of the extracts was comparable to that of the reference standard (hydrochlorothiazide) and the methanol had the additional advantage of a potassium-conserving effect.Conclusion: We can conclude that aqueous and methanol extracts of L. sativum produced notable diuretic effect which appeared to be comparable to that produced by the reference diuretic HCTZ. The present study provides a quantitative basis for explaining the folkloric use of L. sativum as a diuretic agent in Moroccan population
Self-assembling bilayers of palladiumthiolates in organic media
Alkylthiolates of palladium forming a homologous series (butyl to octadecyl) have been prepared and characterized using X-ray diffraction and STM. The thiolates adopt an unusual bilayered lamellar structure, whose thickness is governed by the length of the alkyl chain. These mesophases melt in the temperature range, 60° to 100°C, with the melting point increasing linearly with the thiol chain length. There is evidence to suggest that the alkyl chains are orientationally disordered especially prior to melting
Submicron particles of Co, Ni and Co-Ni alloys
Magnetic sub-micron sized particles (with diameters in the range 100–600 nm) of Co, Ni and Co-Ni alloys, protected with polyvinylpyrrolidone have been prepared in gram quantities using the polyol process. Experiments carried out with different metal precursors and starting compositions have yielded reliable routes to produce particles of the desired diameters in the 100–600 nm range. The particles were characterized with X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, thermogravimetric analysis and magnetic measurements. The particles are found to be stable under ambient conditions indefinitely. The coercivity values of the Co and Ni particles are ∼50% higher compared to the corresponding bulk values. The alloy particles follow a trend similar to the bulk alloys
Inertial Range Scaling, Karman-Howarth Theorem and Intermittency for Forced and Decaying Lagrangian Averaged MHD in 2D
We present an extension of the Karman-Howarth theorem to the Lagrangian
averaged magnetohydrodynamic (LAMHD-alpha) equations. The scaling laws
resulting as a corollary of this theorem are studied in numerical simulations,
as well as the scaling of the longitudinal structure function exponents
indicative of intermittency. Numerical simulations for a magnetic Prandtl
number equal to unity are presented both for freely decaying and for forced two
dimensional MHD turbulence, solving directly the MHD equations, and employing
the LAMHD-alpha equations at 1/2 and 1/4 resolution. Linear scaling of the
third-order structure function with length is observed. The LAMHD-alpha
equations also capture the anomalous scaling of the longitudinal structure
function exponents up to order 8.Comment: 34 pages, 7 figures author institution addresses added magnetic
Prandtl number stated clearl
The Radio Afterglow and Host Galaxy of the Dark GRB 020819
Of the fourteen gamma-ray bursts (GRBs) localized to better than 2' radius
with the SXC on HETE-2, only two lack optical afterglow detections, and the
high recovery rate among this sample has been used to argue that the fraction
of truly dark bursts is ~10%. While a large fraction of earlier dark bursts can
be explained by the failure of ground-based searches to reach appropriate
limiting magnitudes, suppression of the optical light of these SXC dark bursts
seems likely. Here we report the discovery and observation of the radio
afterglow of GRB 020819, an SXC dark burst, which enables us to identify the
likely host galaxy (probability of 99.2%) and hence the redshift (z=0.41) of
the GRB. The radio light curve is qualitatively similar to that of several
other radio afterglows, and may include an early-time contribution from the
emission of the reverse shock. The proposed host is a bright R = 19.5 mag
barred spiral galaxy, with a faint R ~ 24.0 mag "blob'' of emission, 3" from
the galaxy core (16 kpc in projection), that is coincident with the radio
afterglow. Optical photometry of the galaxy and blob, beginning 3 hours after
the burst and extending over more than 100 days, establishes strong upper
limits to the optical brightness of any afterglow or associated supernova.
Combining the afterglow radio fluxes and our earliest R-band limit, we find
that the most likely afterglow model invokes a spherical expansion into a
constant-density (rather than stellar wind-like) external environment; within
the context of this model, a modest local extinction of A_V ~ 1 mag is
sufficient to suppress the optical flux below our limits.Comment: 7 pages, 2 figures. ApJ, in press. For more info on dark bursts, see
http://www.astro.ku.dk/~pallja/dark.htm
Artery tertiary lymphoid organs control multi-layered territorialized atherosclerosis B cell responses in aged ApoE-/- mice
Objective: Explore aorta B cell immunity in aged ApoE-/- mice.
Approach and Results: Transcript maps, FACS, immunofluorescence analyses, cell transfers, and Ig-ELISPOT assays showed multi-layered atherosclerosis B cell responses in artery tertiary lymphoid organs (ATLOs). Aging-associated aorta B cell-related transcriptomes were identified and transcript atlases revealed highly territorialized B cell responses in ATLOs versus atherosclerotic lesions: ATLOs showed upregulation of bona fide B cell genes including Cd19, Ms4a1 (Cd20), Cd79a/b, and Ighm though intima plaques preferentially expressed molecules involved in non-B effector responses towards B cell-derived mediators, i.e. Fcgr3 (Cd16), Fcer1g (Cd23), and the C1q family. ATLOs promoted B cell recruitment. ATLO B-2 B cells included naĂŻve, transitional, follicular, germinal center, switched IgG1+, IgA+, and IgE+ memory cells, plasmablasts, and long-lived plasma cells (PCs). ATLOs recruited large numbers of B-1 cells whose subtypes were skewed towards IL-10+ B-1b cells versus IL-10- B-1a cells. ATLO B-1 cells and PCs constitutively produced IgM and IgG and a fraction of PCs expressed IL-10. Moreover, ApoE-/- mice showed increased germinal center B cells in renal lymph nodes, IgM-producing PCs in the bone marrow, and higher IgM and anti-MDA-LDL IgG serum titers.
Conclusions: ATLOs orchestrate dichotomic, territorialized, and multi-layered B cell responses in the diseased aorta; germinal center reactions indicate generation of autoimmune B cells within the diseased arterial wall during aging
Spitzer Observations of the New Luminous Red Nova M85OT2006-1
M85OT2006-1 is the latest and most brilliant addition to the small group of
known Luminous Red Novae (LRNe). An identifying characteristic of the
previously detected events (M31 RV, V4322 Sgr & V838 Mon) was a spectral
red-ward evolution connected with an emerging infrared component following the
optical decay. Here we report on the discovery of a similar feature in
Keck/NIRC and Spitzer photometry of M85OT2006-1 six months post-eruption. We
find that its 2.1-22 micrometer spectral energy distribution is best described
by a black body with effective temperature T_eff=950+-150 K and bolometric
luminosity L=2.9+-0.5x10^5 L_sun. Assuming spherical geometry, the black body
effective radius, R=2.0+-0.5x10^4 R_sun, and corresponding expansion velocity,
v=870+-260 km/s, are remarkably similar to the properties of M31 RV 70 days
after its eruption. Furthermore, we propose a search strategy for LRNe in the
local Universe making use of the longevity of their infrared excess emission
and discuss the expected number of events in the Spitzer Infrared Nearby
Galaxies Survey.Comment: manuscript after minor revisions, accepted for Ap
Nature and electronic properties of Y-junctions in CNTs and N-doped CNTs obtained by the pyrolysis of organometallic precursors
Carbon nanotubes (CNTs) and N-doped CNTs with Y-junctions have been prepared by the pyrolysis of nickelocene-thiophene and nickel phthalocyanine-thiophene mixtures, respectively, the latter being reported for the first time. The junctions are free from the presence of sulfur and contain only carbon or carbon and nitrogen. The electronic properties of the junction nanotubes have been investigated by scanning tunneling microscopy. Tunneling conductance measurements reveal rectifying behavior with regions of coulomb blockade, the effect being much larger in the N-doped junction nanotubes
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The Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS)
The CLASS experiment on Chandrayaan-2, the second Indian lunar mission, aims tomap the abundance of the major rock forming elements on the lunar surface using the technique of X-ray fluorescence during solar flare events. CLASS is a continuation of the successful C1XS [1] XRF experiment on Chandrayaan-1. CLASS is designed to provide lunar mapping of elemental abundances with a nominal spatial resolution of 25 km (FWHM) from a 200 km polar, circular orbit of Chandrayaan-2
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