581 research outputs found
Analgesic activity of poly herbal formulation in experimental rats by acetic acid induced writhing test model and Hot plate model
To evaluate analgesic activity of a polyherbal formulation-PHF [hydro-alcoholic extract of Hibiscus rosa-sinensis (50mg), Fennel seeds (50mg), Prosopis cineraria (50mg), & Ficus racemosa (50mg)] compare it with Diclofenac Na by using Eddys hot plate and writhing test in Adult Wistar rats. Rats were divided into four groups of 6 each for both tests. PHF (250, 300 mg/kg, p.o. body weight) and Diclofenac Na (50 mg/kg, p.o.) made as suspensions prepared in 1% carboxy methyl cellulose (control) and were fed to rats orally. The physicochemical evaluations carried out in terms of loss on drying, ash value, extractive values and acid insoluble ash value ect. Qualitative analysis of various phytochemical constituents was determined by the well-known test protocol available in the literature. Phytochemical analysis revealed the presence of phenols, flavonoids, tannins, saponins, alkaloids. Analgesic activity was assessed by counting the number of writhes induced by 0.7% acetic acid (10 ml/kg) in the 30 min. Number of writhing and percentage protection against writhing was evaluated. In Eddys hot plate method, they were placed individually on hot plate maintained at a temperature of 55 ± 0.5 ºC. The latency to lick the paw (reaction time) was noted at 0, 30, 60, 90 and 120 min. The cut off time was set at 20 sec to avoid damage to the skin. In acetic acid writhing method, PHF (250, 300 mg/kg, p. o.) significantly (p < 0.001) decreased the number of writhing 39±1.55*, 29.0±0.43*resp. Maximum percentage of inhibition of writhing response shown by Diclofenac Na was 73.03 %. In hot plate method, PHF showed a significant increase in the elevated basal reaction time at 30, 60, 90 and 120 min. The results indicated that the poly-herbal formulation possesses good analgesic activity in the experimental animal models.
Keyword: Analgesic activity, Physicochemical evaluations, Phytochemical analysis, Hibiscus rosa-sinensis Fennel seeds, Prosopis cineraria, Ficus racemos
Natural Color Transparency in High Energy (p,pp) Reactions
New parameter free calculations including a variety of necessary kinematic
and dynamic effects show that the results of BNL measurements are
consistent with the expectations of color transparency.Comment: latex file, 13 pages, 4 figures appended as ps files, look for "cut
here ..." 1993 Univ. of Washington preprint 404427-00-N93-1
Eta meson rescattering effects in the p + 6Li --> eta + 7Be reaction near threshold
The p + 6Li --> eta + 7Be reaction has been investigated with an emphasis on
the eta meson and 7Be interaction in the final state. Considering the 6Li and
7Be nuclei to be alpha-d and alpha-3He clusters respectively, the reaction is
modelled to proceed via the p + d [alpha] --> 3He [\alpha] + eta reaction with
the alpha remaining a spectator. The eta meson interacts with 7Be via multiple
scatterings on the 3He and alpha clusters inside 7Be. The individual eta-3He
and eta-alpha scatterings are evaluated using few body equations for the eta-3N
and eta-4N systems with a coupled channel eta-N interaction as an input.
Calculations including four low-lying states of 7Be lead to a double hump
structure in the total cross section corresponding to the and angular momentum states. The humps
arise due to the off-shell rescattering of the eta meson on the 7Be nucleus in
the final state.Comment: New results and references adde
Composite vertices that lead to soft form factors
The momentum-space cut-off parameter of hadronic vertex functions
is studied in this paper. We use a composite model where we can measure the
contributions of intermediate particle propagations to . We show that
in many cases a composite vertex function has a much smaller cut-off than its
constituent vertices, particularly when light constituents such as pions are
present in the intermediate state. This suggests that composite
meson-baryon-baryon vertex functions are rather soft, i.e., they have \Lambda
considerably less than 1 GeV. We discuss the origin of this softening of form
factors as well as the implications of our findings on the modeling of nuclear
reactions.Comment: REVTex, 19 pages, 5 figs(to be provided on request
Instability of the rhodium magnetic moment as origin of the metamagnetic phase transition in alpha-FeRh
Based on ab initio total energy calculations we show that two magnetic states
of rhodium atoms together with competing ferromagnetic and antiferromagnetic
exchange interactions are responsible for a temperature induced metamagnetic
phase transition, which experimentally is observed for stoichiometric
alpha-FeRh. A first-principle spin-based model allows to reproduce this
first-order metamagnetic transition by means of Monte Carlo simulations.
Further inclusion of spacial variation of exchange parameters leads to a
realistic description of the experimental magneto-volume effects in alpha-FeRh.Comment: 10 pages, 13 figures, accepted for publication in Phys. Rev.
Investigation of the high momentum component of nuclear wave function using hard quasielastic A(p,2p)X reactions
We present theoretical analysis of the first data on the high energy and
momentum transfer (hard) quasielastic reactions. The cross section
of hard reaction is calculated within the light-cone impulse
approximation based on two-nucleon correlation model for the high-momentum
component of the nuclear wave function. The nuclear effects due to modification
of the bound nucleon structure, soft nucleon-nucleon reinteraction in the
initial and final states of the reaction with and without color coherence have
been considered. The calculations including these nuclear effects show that the
distribution of the bound proton light-cone momentum fraction shifts
towards small values (), effect which was previously derived only
within plane wave impulse approximation. This shift is very sensitive to the
strength of the short range correlations in nuclei. Also calculated is an
excess of the total longitudinal momentum of outgoing protons. The calculations
are compared with data on the reaction obtained from the EVA/AGS
experiment at Brookhaven National Laboratory. These data show -shift in
agreement with the calculations. The comparison allows also to single out the
contribution from short-range nucleon correlations. The obtained strength of
the correlations is in agreement with the values previously obtained from
electroproduction reactions on nuclei.Comment: 30 pages LaTex file and 19 eps figure
Color Transparency versus Quantum Coherence in Electroproduction of Vector Mesons off Nuclei
So far no theoretical tool for the comprehensive description of exclusive
electroproduction of vector mesons off nuclei at medium energies has been
developed. We suggest a light-cone QCD formalism which is valid at any energy
and incorporates formation effects (color transparency), the coherence length
and the gluon shadowing. At medium energies color transparency (CT) and the
onset of coherence length (CL) effects are not easily separated. Indeed,
although nuclear transparency measured by the HERMES experiment rises with Q^2,
it agrees with predictions of the vector dominance model (VDM) without any CT
effects. Our new results and observations are: (i) the good agreement with the
VDM found earlier is accidental and related to the specific correlation between
Q^2 and CL for HERMES kinematics; (ii) CT effects are much larger than have
been estimated earlier within the two channel approximation. They are even
stronger at low than at high energies and can be easily identified by HERMES or
at JLab; (iii) gluon shadowing which is important at high energies is
calculated and included; (iv) our parameter-free calculations explain well
available data for variation of nuclear transparency with virtuality and energy
of the photon; (v) predictions for electroproduction of \rho and \phi are
provided for future measurements at HERMES and JLab.Comment: Latex 57 pages and 17 figure
The Role of Color Neutrality in Nuclear Physics--Modifications of Nucleonic Wave Functions
The influence of the nuclear medium upon the internal structure of a
composite nucleon is examined. The interaction with the medium is assumed to
depend on the relative distances between the quarks in the nucleon consistent
with the notion of color neutrality, and to be proportional to the nucleon
density. In the resulting description the nucleon in matter is a superposition
of the ground state (free nucleon) and radial excitations. The effects of the
nuclear medium on the electromagnetic and weak nucleon form factors, and the
nucleon structure function are computed using a light-front constituent quark
model. Further experimental consequences are examined by considering the
electromagnetic nuclear response functions. The effects of color neutrality
supply small but significant corrections to predictions of observables.Comment: 37 pages, postscript figures available on request to
[email protected]
Production and Decay of D_1(2420)^0 and D_2^*(2460)^0
We have investigated and final states and
observed the two established charmed mesons, the with mass
MeV/c and width MeV/c and
the with mass MeV/c and width
MeV/c. Properties of these final states, including
their decay angular distributions and spin-parity assignments, have been
studied. We identify these two mesons as the doublet predicted
by HQET. We also obtain constraints on {\footnotesize } as a function of the cosine of the relative phase of the two
amplitudes in the decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by
sending mail to: [email protected]
Measurement of the branching fraction for
We have studied the leptonic decay of the resonance into tau
pairs using the CLEO II detector. A clean sample of tau pair events is
identified via events containing two charged particles where exactly one of the
particles is an identified electron. We find . The result is consistent with
expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS
94/1297, CLEO 94-20 (submitted to Physics Letters B
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