7,786 research outputs found
Antitumor and cytotoxic potential of various extracts of Gloriosa superba L. Centaurea behen L., Elaeocarpus ganitrus Roxb and Ficus religiosa L. against human breast cancer (MDA-MB 231) cell lines
Background: Medicinal plants are rich in a wide variety of secondary metabolites such as tannins, alkaloids, phenolic compounds, flavonoids etc. which have the capability to inhibit many pathways that lead to cancer. The present study was conducted with the objectives to screen the extracts of dried roots Gloriosa superba L., dried roots of Centaurea behen L. dried fruits/beads of Elaeocarpus ganitrus Roxb., dried leaves of Ficus religiosa L. and investigate their antitumor activity on human breast cancer cell lines (MDA-MB 231).
Methods: Cytotoxic activity was evaluated against non-cancerous cell lines (MCF-10A). Hexane, chloroform, methanol and water were the solvents used for extraction of phytoconstituents by Soxhlet method. Anti-proliferative potential of the plant extracts was evaluated using MTT assay. The trypan blue dye exclusion test was used to determine the number of viable cells present in a cell suspension.
Results: On MDA MB-231 cell lines, 91.94% cell death was reported with G. superba aqueous extract followed by E. ganitrus methanol extract and F. religiosa hexane extract with 87.93% and 81.61% cell death respectively. Moreover, none of the extracts had shown cytotoxic effect while evaluated against normal non-cancerous cell lines (MCF- 10A).
Conclusions: It is inferred from the current findings that phytoconstituents present in the plant extracts have high anticancer potential. These phytoconstituents along with some new anticancer agents present in the plant extracts reflects the high cytotoxic potential against cancer cells
Constraints on the Growth and Spin of the Supermassive Black Hole in M32 From High Cadence Visible Light Observations
We present 1-second cadence observations of M32 (NGC221) with the CHIMERA
instrument at the Hale 200-inch telescope of the Palomar Observatory. Using
field stars as a baseline for relative photometry, we are able to construct a
light curve of the nucleus in the g-prime and r-prime band with 1sigma=36
milli-mag photometric stability. We derive a temporal power spectrum for the
nucleus and find no evidence for a time-variable signal above the noise as
would be expected if the nuclear black hole were accreting gas. Thus, we are
unable to constrain the spin of the black hole although future work will use
this powerful instrument to target more actively accreting black holes. Given
the black hole mass of (2.5+/-0.5)*10^6 Msun inferred from stellar kinematics,
the absence of a contribution from a nuclear time-variable signal places an
upper limit on the accretion rate which is 4.6*10^{-8} of the Eddington rate, a
factor of two more stringent than past upper limits from HST. The low mass of
the black hole despite the high stellar density suggests that the gas liberated
by stellar interactions was primarily at early cosmic times when the low-mass
black hole had a small Eddington luminosity. This is at least partly driven by
a top-heavy stellar initial mass function at early cosmic times which is an
efficient producer of stellar mass black holes. The implication is that
supermassive black holes likely arise from seeds formed through the coalescence
of 3-100 Msun mass black holes that then accrete gas produced through stellar
interaction processes.Comment: 8 pages, 3 figures, submitted to the Astrophysical Journal, comments
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Genetics of Durable Resistance to Leaf Rust in Bread Wheat Cultivars Capelle Desprez and Pari 73
Bread wheat cultivars Capelle Desprez and Pari 73 have been showing adult plant leaf rust resistance in India since 20 years. To examine nature, number and mode of inheritance to leaf rust multipathotype tests were conducted on these cultivars along with reference line RL6058 and HD2009 and the susceptible cultivars WL711 and Agra Local at adult plant stages against the eight leaf rust races. F2 and F3 generations from crosses of Capelle Desprez and Pari 73 with susceptible cultivar WL711 were tested for percent disease severity against leaf rust race 77-5 which suggested the presence of three genes in Capelle Desprez and two genes in Pari 73 to leaf rust. Allelic tests using Capelle Desprez with RL6058 indicated the presence of linked genes Lr34/Yr18 however, presence of transgressive segregants in this cross indicated that the other two genes in Capelle Desprez are also involved in leaf rust resistance. The segregation for susceptible plants observed among all the crosses used for allelic tests of Pari 73 for leaf rust indicated that non-hypersensitive resistance genes in Pari 73 are different from those in RL6058, HD2009 and Capelle Desprez. Studies using 536 primers indicated that one of the three rust resistance gene(s) in cultivar Capelle Desprez is located on chromosome 1B, at a distance of 26.3cM from the primer Xgwm 268. Chromosome location of leaf rust resistance gene from cultivar Pari 73 could not be achieved
Soft x-rays absorption and high-resolution powder x-ray diffraction study of superconducting CaxLa(1-x)Ba(1.75-x)La(0.25+x)Cu3Oy system
We have studied the electronic structure of unoccupied states measured by O
K-edge and Cu L-edge x-ray absorption spectroscopy (XAS), combined with crystal
structure studied by high resolution powder x-ray diffraction (HRPXRD), of
charge-compensated layered superconducting CaxLa(1-x)Ba(1.75-x)La(0.25+x)Cu3Oy
(0<x<0.4, 6.4<y<7.3) cuprate. A detailed analysis shows that, apart from hole
doping, chemical pressure on the electronically active CuO2 plane due to the
lattice mismatch with the spacer layers greatly influences the superconducting
properties of this system. The results suggest chemical pressure to be the most
plausible parameter to control the maximum critical temperatures (Tcmax) in
different cuprate families at optimum hole density.Comment: 14 pages, 11 figures, accepted for publication in Journal of Physics
and Chemistry of Solid
Spring Dispersal of Some Leafhoppers and Aphids
Two species of leafhoppers and four species of cereal aphids appear to be transported to Minnesota each spring on strong winds from the south or southwest. The aster leafhopper, Macrosteles fascifrons (Stal); the English grain aphid, Macrosiphum avenae (Fabr.); the apple grain aphid, Rhopalosiphum fitchii (Sand.); and the greenbug, Schizaphis graminum (Rond.), usually arrive in Minnesota during late April or early May. Weather conditions favorable for northward movement of these insects consist of a high pressure area over the eastern states, a low pressure area over the western plains, and the resulting strong, persistent, south wind which is often called a low-level jet. The potato leafhopper, Empoasca fabae (Harris), usually arrives in southern Minnesota about May 20 and in central Minnesota about May 25. By mid-June it has usually dispersed to the northern part of the state. The corn leaf aphid, Rhopalosiphum maidis (Fitch), usually arrives during early June
Editorial: Advances in Endocrinology: Stem Cells and Growth Factors
Stem Cells investigation in Endocrinology: leading stem cell scientists and developmental endocrinologists, critically review both cutting-edge approaches to stem cell biology and the application of stem cells and their secretome to translational/precision medicine, endocrine diseases, including diabetes, tissue/organ repairs, energy metabolism, and metabolic disorders
Direct Visualization of Laser-Driven Focusing Shock Waves
Cylindrically or spherically focusing shock waves have been of keen interest
for the past several decades. In addition to fundamental study of materials
under extreme conditions, cavitation, and sonoluminescence, focusing shock
waves enable myriad applications including hypervelocity launchers, synthesis
of new materials, production of high-temperature and high-density plasma
fields, and a variety of medical therapies. Applications in controlled
thermonuclear fusion and in the study of the conditions reached in laser fusion
are also of current interest. Here we report on a method for direct real-time
visualization and measurement of laser-driven shock generation, propagation,
and 2D focusing in a sample. The 2D focusing of the shock front is the
consequence of spatial shaping of the laser shock generation pulse into a ring
pattern. A substantial increase of the pressure at the convergence of the
acoustic shock front is observed experimentally and simulated numerically.
Single-shot acquisitions using a streak camera reveal that at the convergence
of the shock wave in liquid water the supersonic speed reaches Mach 6,
corresponding to the multiple gigapascal pressure range 30 GPa
Effect of Pt substitution on the electronic structure of AuTe2
We report a photoemission and x-ray absorption study on Au1-xPtxTe2 (x = 0
and 0.35) triangular lattice in which superconductivity is induced by Pt
substitution for Au. Au 4f and Te 3d core-level spectra of AuTe2 suggests a
valence state of Au2+(Te2)2-, which is consistent with its distorted crystal
structure with Te-Te dimers and compressed AuTe6 otahedra. On the other hand,
valence-band photoemission spectra and pre-edge peaks of Te 3d absorption edge
indicate that Au 5d bands are almost fully occupied and that Te 5p holes govern
the transport properties and the lattice distortion. The two apparently
conflicting pictures can be reconciled by strong Au 5d/Au 6s-Te 5p
hybridization. Absence of a core-level energy shift with Pt substitution is
inconsistent with the simple rigid band picture for hole doping. The Au 4f
core-level spectrum gets slightly narrow with Pt substitution, indicating that
the small Au 5d charge modulation in distorted AuTe2 is partially suppressed.Comment: 13 pages, 4 figures, accepted by Physical Review
Anisotropy dissipation in brane-world inflation
We examine the behavior of an anisotropic brane-world in the presence of
inflationary scalar fields. We show that, contrary to naive expectations, a
large anisotropy does not adversely affect inflation. On the contrary, a large
initial anisotropy introduces more damping into the scalar field equation of
motion, resulting in greater inflation. The rapid decay of anisotropy in the
brane-world significantly increases the class of initial conditions from which
the observed universe could have originated. This generalizes a similar result
in general relativity. A unique feature of Bianchi I brane-world cosmology
appears to be that for scalar fields with a large kinetic term the initial
expansion of the universe is quasi-isotropic. The universe grows more
anisotropic during an intermediate transient regime until anisotropy finally
disappears during inflationary expansion.Comment: 6 pages, 5 figures; minor typo corrected in Eq. (16); matches version
to appear in Phy Rev
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