Domain formation and growth in spinodal decomposition of a binary fluid by molecular dynamics simulations

The two initial stages of spinodal decomposition of a symmetric binary Lennard-Jones fluid have been simulated by molecular dynamics simulations, using a hydrodynamics-conserving thermostat. By analyzing the growth of the average domain size R(t) with time, a satisfactory agreement is found with the R(t)t1/3 Lifshitz-Slyozov growth law for the early diffusion-driven stage of domain formation in a quenched homogeneous mixture. In the subsequent stage of viscous-dominated growth, the mean domain size appears to follow the linear growth law predicted by Siggia

How large can the branching ratio of Bs→τ+τ−B_s \to \tau^+ \tau^- be ?

Motivated by the large like-sign dimuon charge asymmetry observed recently, whose explanation would require an enhanced decay rate of $B_s \to \tau^+ \tau^-$, we explore how large a branching ratio of this decay mode is allowed by the present constraints. We use bounds from the lifetimes of $B_d$ and $B_s$, constraints from the branching ratios of related $b \to s \tau^+ \tau^-$ modes, as well as measurements of the mass difference, width difference and CP-violating phase in the $B_s$-$\bar{B}_s$ system. Using an effective field theory approach, we show that a branching ratio as high as 15% may be allowed while being consistent with the above constraints. The model with a scalar leptoquark cannot increase the branching ratio to a per cent level. However, an enhancement up to 5% is possible in the model with an extremely light $Z'$ with flavor-dependent interactions, even after all the couplings are taken to be perturbative. This however cannot account for the dimuon anomaly completely by itself.Comment: Typos corrected, some discussions added, accepted for publication in Phys.Rev.

Analytical method development and validation for the determination of Brinzolamide by RP-HPLC

Brinzolamide is inhibitor of carbonic anhydride and is highly specific and non-competitive. The aim of the present study is to develop a simple, precise, accurate, sensitive RP-HPLC method for the determination of bulk drug. The objective of the method validation is to demonstrate whether the method was suited for the intended purpose. The method was validated as per the ICH guidelines. The method was validated for linearity, precision (repeatability, intermediate precision), accuracy, specificity, robustness, ruggedness, limit of detection and limit of quantification. Cosmosil (4.6X250mm, 5 μ) column was used for separation. The selected wavelength for Brinzolamide was 254 nm. The mobile phase consists of Acetonitrile: Potassium dihydrogen phosphate buffer (40:60). Flow rate was delivered at 1.0 mL/min. Appropriate dilutions of standard stock solutions were prepared to get desired concentrations in the range of 100-500 mcg/ml. The equation od standard curve was y = 441.8x + 1132 and R2 = 0.998. The RT obtained was 6.6167 minutes. Keywords: Brinzolamide, UV spectroscopy, RP-HPLC, IC

Discovering High Utility Itemsets using Hybrid Approach

Mining of high utility itemsets especially from the big transactional databases is time consuming task. For mining the high utility itemsets from large transactional datasets multiple methods are available and have some consequential limitations. In case of performance these methods need to be scrutinized under low memory based systems for mining high utility itemsets from transactional datasets as well as to address further measures. The proposed algorithm combines the High Utility Pattern Mining and Incremental Frequent Pattern Mining. Two algorithms used are Apriori and existing Parallel UP Growth for mining high utility itemsets using transactional databases. The information about high utility itemsets is maintained in a data structure called UP tree. These algorithms are not only used to scans the incremental database but also collects newly generated frequent itemsets support count. It provides fast execution because it includes new itemsets in tree and removes rare itemset from a utility pattern tree structure that reduces cost and time. From various Experimental analysis and results, this hybrid approach with existing Apriori and UP-Growth is proposed with aim of improving the performance

Development and Validation of Stability Indicating RP-HPLC Method for Estimation of Cilnidipine

Cilnidipine is one of the dihydropyridine calcium antagonists. It was created combinedly by Fuji Viscera Pharmaceutical Company, Ajinomoto and Japan and was approved in the year 1995. Cilnidipine acts on N-type calcium channel where exist the end of sympathetic nerve in addition to common L-type calcium channel like that of other calcium antagonists. China, Japan, India, Korea and several other countries approved this drug. The objective of the method validation is to demonstrate whether the method was suited for the intended purpose. The method was validated as per the ICH guidelines. The method was validated for linearity, precision (repeatability, intermediate precision), accuracy, specificity, robustness, limit of detection and limit of quantification. Cosmosil (4.6 X 250mm, 5 μ) column was used for separation. The selected wavelength for Cilnidipine was 241 nm. The mobile phase consists Methanol: Potassium dihydrogen phosphate buffer (50:50). Flow rate was delivered at 1.0 mL/min. Appropriate dilutions of standard stock solutions were prepared as per the get desired concentrations in the range of 100-500 mcg/ml. The RT obtained was 4.8165 minutes. Keywords: Cilnidipine, UV spectroscopy, RP-HPLC, IC

Effect of tianeptine on seizure threshold and anticonvulsant activity of valproate, phenobarbitone and phenytoin in mice

Background: Depression is a common psychiatric comorbidity in patients with epilepsy and often remains untreated due to concern of antidepressant induced seizures. Tricyclic antidepressants, norepinephrine reuptake inhibitors and bupropion have been shown to increase the risk of seizures. Selective serotonin reuptake inhibitors and venlafaxine have shown both anticonvulsant and proconvulsant activity. The information on anticonvulsant effects of tianeptine, a newer antidepressant, is limited to few animal studies. In view of this, the present study was undertaken to investigate the anticonvulsant activity of tianeptine and its interaction with conventional antiepileptic drugs (AEDs) viz. valproate, phenobarbitone and phenytoin in mice.Methods: The study was carried out in 3 phases using healthy adult male mice. In phase I, effect of oral administration of tianeptine on seizure threshold was studied using electroconvulsive threshold method. In phase II and phase III, effect of tianeptine on median effective dose (ED50) of valproate, phenobarbitone and phenytoin was studied using maximal electroshock seizure (MES) test after administering tianeptine with these AEDs in various combinations. In phase II, drugs were administered orally once while in phase III, these were daily administered orally for 28 days.Results: In phase I, tianeptine increased electroconvulsive threshold in dose dependent manner but effect was significant only at 20 and 40 mg/kg (P<0.05 and 0.001 respectively). In phase II and III, tianeptine exhibited dose dependent reduction in ED50 of all the studied AEDs, however, significant reduction of ED50 of valproate and phenobarbitone (P<0.05 for both) was observed only when tianeptine was administered at 40 mg/kg, while significant reductions in ED50 of phenytoin were observed when tianeptine was administered as 20 and 40 mg/kg (P<0.05 and 0.01 respectively) and in phase III, significant reduction of ED50 value of valproate (P<0.01) and phenobarbitone (P<0.05) was observed with tianeptine at 40 mg/kg while reduction in ED50 of phenytoin was significant at all the studied doses of tianeptine with P<0.05 at 10 and 20 mg/kg and P<0.01 at 40mg/kg..Conclusions: Tianeptine exhibits anticonvulsant action which is synergistic with anticonvulsant effects of valproate, phenobarbitone and phenytoin suggesting that tianeptine may be a safe option in patients of epilepsy concurrently suffering from depression