243 research outputs found
The Cytotoxic Effect of Pinostrobin Fingerroot (Boesenbergia Pandurata)on the Culture of Hela Cells
Background : Cancer is one of the leading causes of death worldwide, therefore struggles to find more effective treatment and prevention is needed. Several studies has been performed using natural ingredients, one of which is Temu Kunci (B. pandurata). Temu Kunci extract contains flavonoid pinostrobin that has been showed as having cytotoxicity effects. Cytotoxicity tests of pinostrobin have been performed on several tumor cell lines, but its cytotoxicity effect on HeLa cell line has never been reported. Objective : To assess cytotoxicity effect of pinostrobin temu kunci on HeLa cell culture Methods : This study used simple experimental design. Pinostrobin were isolated from temu kunci and proved by TLC densitometry compared to standard pinostrobin. HeLa cell culture were treated with pinostrobin with concentrations 5, 25, 50, 75, 100, and 250 ug/mL. Cytotoxicity test were performed by MTT assay. Data were analyzed using one-way ANOVA. Results : There was significant difference (p=0.000) of means of cell viability percentage, respectively: 92.58 ± 9.84 (5μg/mL), 91.78 ± 4.4 (25μg/mL), 80.09 ± 4.51 (50μg/mL), 76.89 ± 7.75 (75μg/mL), 67.85 ± 11.31 (100μg/mL), dan 48.82 ± 16.61 (250μg/mL). The IC50 was 250μg/mL. Conclusion : Pinostrobin showed no active cytotoxicity effect on HeLa cell culture
Molecular Identification, Antimicrobial and Antioxidant Activities of the Tropical Seagrass Halophila stipulacea Grown in El-Bardawil Lake, Egypt
Abstract: Halophila stipulacea a tropical seagrass entered the Mediterranean Sea from the Red Sea after the opening of the Suez Canal in 1869. Up to date, no genetic studies of Halophila stipulacea from El-Bardawil Lake are available. In order to verify the molecular identity of El-Bardawil lake isolates of Halophila stipulacea, employing Random Amplified Polymorphic analysis (RAPD) which carried out using six decamer primers, 26 amplified bands were produced, the highest number of amplified fragments (11 fragments) was produced by primer OP C04 and the OP B07 whereas OPC03 was the lowest primer (7 fragments). In this study, aqueous extract from Halophila stipulacea was assayed against some microorganisms using zone inhibition technique. The extract showed moderate activity against Gram-positive bacteria and high activity against filamentous Aspergillus niger fungus. In addition the antioxidant activity of the methanolic extract was studied and showed a moderate activity of the Halophila stipulacea seagrass reached 40%. The total phenolic content in the seagrass extract was 0.523 mg tannic acid equivalent /g
Hyperon Nonleptonic Decays in Chiral Perturbation Theory Reexamined
We recalculate the leading nonanalytic contributions to the amplitudes for
hyperon nonleptonic decays in chiral perturbation theory. Our results partially
disagree with those calculated before, and include new terms previously omitted
in the P-wave amplitudes. Although these modifications are numerically
significant, they do not change the well-known fact that good agreement with
experiment cannot be simultaneously achieved using one-loop S- and P-wave
amplitudes.Comment: 14 pages, latex, 3 figures, uses axodraw.sty, minor additions, to
appear in Phys. Rev.
Decay constants, semi-leptonic and non-leptonic decays in a Bethe-Salpeter Model
We evaluate the decay constants for the B and mesons and the form factors
for the semileptonic decays of the B meson to and mesons in a
Bethe-Salpeter model. From data we extract from and from decays. The form factors are then used to obtain non-leptonic
decay partial widths for and in the
factorization approximation.Comment: 15 Pages, 3 Postscript figures (available also from [email protected]
Obtaining CKM Phase Information from B Penguin Decays
We discuss a method for extracting CP phases from pairs of B decays which are
related by flavor SU(3). One decay (B0 -> M1 M2) receives a significant bbar ->
dbar penguin contribution. The second (B' -> M1' M2') has a significant bbar ->
sbar penguin contribution, but is dominated by a single amplitude. CP phase
information is obtained using the fact that the B' -> M1' M2' amplitude is
related by SU(3) to a piece of the B0 -> M1 M2 amplitude. The leading-order
SU(3)-breaking effect (~25%) responsible for the main theoretical error can be
removed. For some decay pairs, it can be written in terms of known decay
constants. In other cases, it involves a ratio of form factors. However, this
form-factor ratio can either be measured experimentally, or eliminated by
considering a double ratio of amplitudes. In all cases, one is left only with a
second-order effect, ~5%. We find twelve pairs of B decays to which this method
can be applied. Depending on the decay pair, we estimate the total theoretical
error in relating the B' -> M1' M2' and B0 -> M1 M2 amplitudes to be between 5%
and 15%. The most promising decay pairs are Bd -> pi+ pi- and Bu+ -> K0 pi+,
and Bd -> D+ D- and Bd -> Ds+ D- or Bu+ -> Ds+ D0bar.Comment: 38 pages, JHEP format, no figures. Comments added to text regarding
most promising decay pairs; references added; conclusions unchange
Constraints on from Radiative Hyperon and Kaon Decays
The quark-level process has been used extensively to place
constraints on new interactions. These same interactions can be further
constrained from the enhancement they induce in the quark-level transition, to the extent that the short distance contributions can be
separated from the long distance contributions. We parameterize what is known
about the long distance amplitudes and subtract it from the data in radiative
hyperon and kaon decays to constrain new interactions.Comment: Latex 11 page
Bethe-Salpeter equation and a nonperturbative quark-gluon vertex
A Ward-Takahashi identity preserving Bethe-Salpeter kernel can always be
calculated explicitly from a dressed-quark-gluon vertex whose diagrammatic
content is enumerable. We illustrate that fact using a vertex obtained via the
complete resummation of dressed-gluon ladders. While this vertex is planar, the
vertex-consistent kernel is nonplanar and that is true for any dressed vertex.
In an exemplifying model the rainbow-ladder truncation of the gap and
Bethe-Salpeter equations yields many results; e.g., pi- and rho-meson masses,
that are changed little by including higher-order corrections. Repulsion
generated by nonplanar diagrams in the vertex-consistent Bethe-Salpeter kernel
for quark-quark scattering is sufficient to guarantee that diquark bound states
do not exist.Comment: 16 pages, 12 figures, REVTEX
Final State Interactions and New Physics in B -> pi K Decays
Within the Standard Model, and if one assumes that soft rescattering effects
are negligible, the CP asymmetry A^dir_CP (B^\pm -> \pi^\pm K) is predicted to
be very small and the ratio R = BR(B_d -> \pi^\mp K^\pm)/BR(B^\pm -> \pi^\pm K)
provides a bound on the angle \gamma of the unitarity triangle, sin^2 \gamma
\leq R. We estimate the corrections from soft rescattering effects using an
approach based on Regge phenomenology, and find effects of order 10% with large
uncertainties. In particular, we conclude that A^dir_CP \sim 0.2 and sin^2
\gamma \sim 1.2 R could not be taken unambiguously to signal New Physics. Using
SU(3) relations, we suggest experimental tests that could constrain the size of
the soft rescattering effects thus reducing the related uncertainty. Finally,
we study the effect of various models of New Physics on A^dir_CP and on R.Comment: 20 pages, RevTex, no figures; a few typos corrected, references
added, brief additional discussion of uncertanties is adde
Lattice models and Landau theory for type II incommensurate crystals
Ground state properties and phonon dispersion curves of a classical linear
chain model describing a crystal with an incommensurate phase are studied. This
model is the DIFFOUR (discrete frustrated phi4) model with an extra
fourth-order term added to it. The incommensurability in these models may arise
if there is frustration between nearest-neighbor and next-nearest-neighbor
interactions. We discuss the effect of the additional term on the phonon
branches and phase diagram of the DIFFOUR model. We find some features not
present in the DIFFOUR model such as the renormalization of the
nearest-neighbor coupling. Furthermore the ratio between the slopes of the soft
phonon mode in the ferroelectric and paraelectric phase can take on values
different from -2. Temperature dependences of the parameters in the model are
different above and below the paraelectric transition, in contrast with the
assumptions made in Landau theory. In the continuum limit this model reduces to
the Landau free energy expansion for type II incommensurate crystals and it can
be seen as the lowest-order generalization of the simplest Lifshitz-point
model. Part of the numerical calculations have been done by an adaption of the
Effective Potential Method, orginally used for models with nearest-neighbor
interaction, to models with also next-nearest-neighbor interactions.Comment: 33 pages, 7 figures, RevTex, submitted to Phys. Rev.
CP asymmetries in B0 decays in the left-right model
We study time dependent CP asymmetries in B^0_{d,s} decays in the left-right
model with spontaneous breakdown of CP. Due to the new contributions to
B^0-\bar B^0 mixing the CP asymmetries can be substantially modified. Moreover,
there can be significant new contributions to the -meson decay amplitudes
from the magnetic penguins. Most promising for detection of the new physics in
the planned factories is that the CP asymmetries in the decays B--> J/\psi
K_S and B--> \phi K_S which are supposed to be equal in the standard model can
differ significantly in this class of models independently of the results in
the measurements of B--> X_s \gamma.Comment: Revised version, to appear in PR
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