Solubility and dissolution enhancement of poorly aqueous soluble drug atorvastatin calcium using modified gum karaya as carrier: In vitro-In vivo evaluation

Solid dispersion is a unique and promising approach for improving the oral absorption and oral bioavailability of BCS class II drugs. Modified gum karaya a recently developed excipient was evaluated as a carrier for solubility and dissolution enhancement of poorly water soluble drug atorvastatin calcium. Physical mixtures along with solid dispersions of drug and polymer was  prepared using three methods kneading, solvent evaporation and solvent wetting method in 5 different ratios (1:1,1:3,1:5,1:7,1:9). Among the three methods used atorvastatin calcium solid dispersions prepared by kneading method in 1:3 ratio showed most promising results in terms of  percent yield, percent drug content, solubility of solid dispersions in phosphate buffer pH 6.8, XRD, DSC, SEM and In vitro release studies. These solid dispersions were selected to prepare tablets using Ac-di-sol as superdisintegrant (T1, T2, T3, T4 and T5). Tablets were characterized for hardness, friability, disintegration time, percent drug content, drug release studies and stability studies. Tablets T5 showed highest dissolution rate and best dissolution efficiency at (DE30) and (DE120) minutes. Release data of T5 tablet was subjected to various release kinetics models to know the type and order of drug release. Order was found to be Korsemeyer–Peppas>Hixson–Crowell cube root law >zero-order >first-order >Higuchi. The similarity factor was calculated for comparison of the dissolution profile before and after stability studies. The f2 value was found to be more than 50 (~ 90.9) thereby indicating a close similarity between both the dissolution profiles. In vivo studies was conducted on healthy albino rats and formulation given by oral route showed that at the end of 14 days solid dispersion 1:3 performed better than pure atorvastatin calcium in reducing total cholesterol and TG level and increasing HDL- cholesterol levels

Explicit Model Checking of Very Large MDP using Partitioning and Secondary Storage

The applicability of model checking is hindered by the state space explosion problem in combination with limited amounts of main memory. To extend its reach, the large available capacities of secondary storage such as hard disks can be exploited. Due to the specific performance characteristics of secondary storage technologies, specialised algorithms are required. In this paper, we present a technique to use secondary storage for probabilistic model checking of Markov decision processes. It combines state space exploration based on partitioning with a block-iterative variant of value iteration over the same partitions for the analysis of probabilistic reachability and expected-reward properties. A sparse matrix-like representation is used to store partitions on secondary storage in a compact format. All file accesses are sequential, and compression can be used without affecting runtime. The technique has been implemented within the Modest Toolset. We evaluate its performance on several benchmark models of up to 3.5 billion states. In the analysis of time-bounded properties on real-time models, our method neutralises the state space explosion induced by the time bound in its entirety.Comment: The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-24953-7_1

Rapidity and Centrality Dependence of Proton and Anti-proton Production from Au+Au Collisions at sqrt(sNN) = 130GeV

We report on the rapidity and centrality dependence of proton and anti-proton transverse mass distributions from Au+Au collisions at sqrt(sNN) = 130GeV as measured by the STAR experiment at RHIC. Our results are from the rapidity and transverse momentum range of |y|<0.5 and 0.35 <p_t<1.00GeV/c. For both protons and anti-protons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within |y|<0.5. Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton(anti-proton) yields and transverse mass distributions the possibility of pre-hadronic collective expansion may have to be taken into account.Comment: 4 pages, 3 figures, 1 table, submitted to PR

Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Azimuthal anisotropy and correlations at large transverse momenta in p+pp+p and Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV

Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at $\sqrt{s_{_{NN}}}$= 200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in $p+p$ at the same energy. Elliptic anisotropy, $v_2$, is found to reach its maximum at $p_t \sim 3$ GeV/c, then decrease slowly and remain significant up to $p_t\approx 7$ -- 10 GeV/c. Stronger suppression is found in the back-to-back high-$p_t$ particle correlations for particles emitted out-of-plane compared to those emitted in-plane. The centrality dependence of $v_2$ at intermediate $p_t$ is compared to simple models based on jet quenching.Comment: 4 figures. Published version as PRL 93, 252301 (2004

Role of folic acid supplementation in prevention of neural tube defects: physicians yet unaware!

Folic acid supplementation is important in the prevention of Neural Tube Defects (NTD). The study was conducted to assess the awareness amongst physicians regarding the role of Folic Acid (FA) in the prevention of NTD. Physicians were interviewed regarding the awareness of FA dose, timing of supplementation and knowledge about its role in prevention of neural tube defects using a semistructured questionnaire. Among 202 physicians interviewed (48 pediatricians, 54 obstetricians, 100 recently qualified medical graduates) overall awareness about FA was present in 92.07%, similar in three groups (P > 0.05). Only 47.52% were aware of preconception administration, 61.38% about dose of supplementation and 11.88% about recurrence rate of NTD. Only 15 (7.4%) knew all these. Regarding the etiology of NTDs only 26.7% said both FA and genetic factors are involved. Though majority were aware that folic acid has a role in prevention of NTDs, their knowledge about timing and dose of supplementation was lacking. Hence attempts should be made to increase the awareness regarding prevention of NTD?s by FA supplementation at a proper time

Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV

The results from the STAR Collaboration on directed flow (v_1), elliptic flow (v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. Different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v_2, scaling with the number of constituent quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures modified, but data the same. However, in Fig. 35 the hydro calculations are corrected in this version. The data tables are available at http://www.star.bnl.gov/central/publications/ by searching for "flow" and then this pape

Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at root s=200 GeV

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at root200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at roots less than or equal to20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider

Azimuthal anisotropy at the relativistic heavy ion collider: The first and fourth harmonics

We report the first observations of the first harmonic (directed flow, v(1)) and the fourth harmonic (v(4)), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v(2)) generated at RHIC. From the correlation of v(2) with v(1) it is determined that v(2) is positive, or in-plane. The integrated v(4) is about a factor of 10 smaller than v(2). For the sixth (v(6)) and eighth (v(8)) harmonics upper limits on the magnitudes are reported