Antioxidant Properties of Bitter Gourd (Momordica Charantia L.)

Bitter gourd is regarded as an antioxidant rich vegetable with beneficial properties for the circulatory, respiratory, digestive and nervous systems according to the Indian indigenous system of medicine. Several methods have been used to determine antioxidant activity of plants. The present study, therefore, involved four various established methods to evaluate anti oxidative activity of bitter gourd fruit, namely, total antioxidant capacity, DPPH radical scavenging activity, hydroxyl radical scavenging activity and super oxide anion radical scavenging activity by using different types of solvents like petroleum ether, acetone, ethanol and methanol. The present study revealed that light green big sample had the highest DPPH activity with an IC50 value of 50.88 µg/ ml in methanol solvent. In the case of bitter gourd dried samples, highest DPPH activity with an IC50 value of 50.10 µg/ ml was reported in light green big type. The hydroxyl radical scavenging activity of light green big was found to be highest both in the case of fresh and dried bitter gourd samples with an IC50 values of 50.95 µg/ml and 50.10 µg/ml respectively. Light green small sample showed higher superoxide anion radical scavenging activity with an IC50 value of 50.36 µg/ ml in fresh samples and 49.76 µg/ ml in dried samples, in solvents like petroleum ether and acetone respectively. Antioxidant activity ranged with an IC50 value of 50.09 µg/ml to 61.90 µg/ml in fresh bitter gourd samples and maximum antioxidant capacity was observed in light green big (50.09 µg/ ml) whereas dried samples, the highest antioxidant activity was observed in light green dried (50.07 µg/ ml) in acetone solvent

Competing orders II: the doped quantum dimer model

We study the phases of doped spin S=1/2 quantum antiferromagnets on the square lattice, as they evolve from paramagnetic Mott insulators with valence bond solid (VBS) order at zero doping, to superconductors at moderate doping. The interplay between density wave/VBS order and superconductivity is efficiently described by the quantum dimer model, which acts as an effective theory for the total spin S=0 sector. We extend the dimer model to include fermionic S=1/2 excitations, and show that its mean-field, static gauge field saddle points have projective symmetries (PSGs) similar to those of `slave' particle U(1) and SU(2) gauge theories. We account for the non-perturbative effects of gauge fluctuations by a duality mapping of the S=0 dimer model. The dual theory of vortices has a PSG identical to that found in a previous paper (L. Balents et al., cond-mat/0408329) by a duality analysis of bosons on the square lattice. The previous theory therefore also describes fluctuations across superconducting, supersolid and Mott insulating phases of the present electronic model. Finally, with the aim of describing neutron scattering experiments, we present a phenomenological model for collective S=1 excitations and their coupling to superflow and density wave fluctuations.Comment: 22 pages, 10 figures; part I is cond-mat/0408329; (v2) changed title and added clarification

REVIEW ON EVALUATING THE ROLE OF NSAIDS FOR THE TREATMENT OF ALZHEIMER'S DISEASE

Recently, several studies have been reported that nonsteroidal anti-inflammatory drugs can fight against neurodegenerative disorders by various mechanisms. Currently, available therapies of neurodegenerative disorders (NDs) provide only symptomatic relief. This is the point at which we need an alternative that acts on the root cause of disease. Parkinson’s disease and Alzheimer’s disease are the two NDs concentrated here. Since the drug profile is already known, drug repurposing is a promising technique in research, thereby reducing the cost and period effectively. Epidemiological studies on various nonsteroidal anti-inflammatory drugs (NSAIDs) showed good results, but when it came to clinical studies the results are found to be poor. Hence, it can be concluded that NSAIDs provide its neuroprotective activity on its long-term use only, as the brain accessibility of this kind of drug is poor due to its lower lipophilicity

Non-equilibrium Dynamics of O(N) Nonlinear Sigma models: a Large-N approach

We study the time evolution of the mass gap of the O(N) non-linear sigma model in 2+1 dimensions due to a time-dependent coupling in the large-$N$ limit. Using the Schwinger-Keldysh approach, we derive a set of equations at large $N$ which determine the time dependent gap in terms of the coupling. These equations lead to a criterion for the breakdown of adiabaticity for slow variation of the coupling leading to a Kibble-Zurek scaling law. We describe a self-consistent numerical procedure to solve these large-$N$ equations and provide explicit numerical solutions for a coupling which starts deep in the gapped phase at early times and approaches the zero temperature equilibrium critical point $g_c$ in a linear fashion. We demonstrate that for such a protocol there is a value of the coupling $g= g_c^{\rm dyn}> g_c$ where the gap function vanishes, possibly indicating a dynamical instability. We study the dependence of $g_c^{\rm dyn}$ on both the rate of change of the coupling and the initial temperature. We also verify, by studying the evolution of the mass gap subsequent to a sudden change in $g$, that the model does not display thermalization within a finite time interval $t_0$ and discuss the implications of this observation for its conjectured gravitational dual as a higher spin theory in $AdS_4$.Comment: 22 pages, 9 figures. Typos corrected, references rearranged and added.v3 : sections rearranged, abstract modified, comment about Kibble-Zurek scaling correcte

QCD sum rules at finite temperature

We derive thermal QCD sum rules for the correlation function of two vector currents in the rho-meson channel. It takes into account the leading non-perturbative corrections from the additional operators, which appear due to the breakdown of Lorentz invariance at finite temperature. The mixing of the new operators has a drastic effect on their coefficients. The thermal average of all the operators can be related to that of the quark condensate and the energy density. The sum rules then yield the temperature dependence of the parameters of the $\rho$-meson, namely its mass and coupling to the vector current. Our result is that these parameters are practically independent of temperature at least up to a temperature of 125 MeV.Comment: 11 pages, revtex, 2 figure

Evolution of cooperation in stochastic games

Social dilemmas occur when incentives for individuals are misaligned with group interests 1-7 . According to the 'tragedy of the commons', these misalignments can lead to overexploitation and collapse of public resources. The resulting behaviours can be analysed with the tools of game theory 8 . The theory of direct reciprocity 9-15 suggests that repeated interactions can alleviate such dilemmas, but previous work has assumed that the public resource remains constant over time. Here we introduce the idea that the public resource is instead changeable and depends on the strategic choices of individuals. An intuitive scenario is that cooperation increases the public resource, whereas defection decreases it. Thus, cooperation allows the possibility of playing a more valuable game with higher payoffs, whereas defection leads to a less valuable game. We analyse this idea using the theory of stochastic games 16-19 and evolutionary game theory. We find that the dependence of the public resource on previous interactions can greatly enhance the propensity for cooperation. For these results, the interaction between reciprocity and payoff feedback is crucial: neither repeated interactions in a constant environment nor single interactions in a changing environment yield similar cooperation rates. Our framework shows which feedbacks between exploitation and environment - either naturally occurring or designed - help to overcome social dilemmas

Universal Stress Proteins Are Important for Oxidative and Acid Stress Resistance and Growth of Listeria monocytogenes EGD-e In Vitro and In Vivo

Background: Pathogenic bacteria maintain a multifaceted apparatus to resist damage caused by external stimuli. As part of this, the universal stress protein A (UspA) and its homologues, initially discovered in Escherichia coli K-12 were shown to possess an important role in stress resistance and growth in several bacterial species. Methods and Findings: We conducted a study to assess the role of three homologous proteins containing the UspA domain in the facultative intracellular human pathogen Listeria monocytogenes under different stress conditions. The growth properties of three UspA deletion mutants (deltalmo0515, deltalmo1580 and deltalmo2673) were examined either following challenge with a sublethal concentration of hydrogen peroxide or under acidic conditions. We also examined their ability for intracellular survival within murine macrophages. Virulence and growth of usp mutants were further characterized in invertebrate and vertebrate infection models. Tolerance to acidic stress was clearly reduced in Δlmo1580 and deltalmo0515, while oxidative stress dramatically diminished growth in all mutants. Survival within macrophages was significantly decreased in deltalmo1580 and deltalmo2673 as compared to the wild-type strain. Viability of infected Galleria mellonella larvae was markedly higher when injected with deltalmo1580 or deltalmo2673 as compared to wild-type strain inoculation, indicating impaired virulence of bacteria lacking these usp genes. Finally, we observed severely restricted growth of all chromosomal deletion mutants in mice livers and spleens as compared to the load of wild-type bacteria following infection. Conclusion: This work provides distinct evidence that universal stress proteins are strongly involved in listerial stress response and survival under both in vitro and in vivo growth conditions