Streaming Potential and Associated Electrokinetic Effects through a Channel Filled with Electrolyte Solution Surrounded by a Layer of Immiscible and Dielectric Liquid.

The present article deals with the streaming potential-mediated pressure-driven flow across a channel in which the electrolyte solution is surrounded by a layer of cell membrane. Such a membrane of a biological cell may be modeled as an immiscible and dielectric liquid, which may bear free lipid molecules or charged surfactants. The presence of such additional charged molecules may lead to formation of liquid-liquid interfacial charge. In addition, the dielectric gradient-mediated ion partitioning effect further plays an important role in two-phase electrokinetic motion. We aim to study the generation of streaming potential and electrokinetic conversion efficiency as well as associated electroviscous effect for the undertaken problem. The mathematical model is based on the Poisson-Boltzmann equation for electrostatic potential and the Stokes equation for fluid flow, and the problem is studied considering suitable interfacial conditions for the flow variables along the liquid-liquid interface. The explicit analytical results for velocity and streaming field, electrokinetic energy conversion efficiency, and the parameter indicating the electroviscous effect are derived under the Donnan limit and within the Debye-Hückel electrostatic framework. We further numerically calculated the aforementioned intrinsic electrokinetic parameter associated with the problem undertaken for a wide range of pertinent parameters. The results are illustrated to indicate the impact of pertinent parameters on the generation of the streaming potential and associated electrokinetic effects.

Validation of Unani concept of Abadal-i-Adwiya (drug substitution) by physicochemical standardization and hepatoprotective activity of Aristolochia rotunda Linn. and its substitute Curcuma Zedoaria Rosc. in albino Wistar rats.

OBJECTIVES: To validate the concept of abadal-i-adwiya (drug substitution) by evaluation of physicochemical standardization and hepatoprotective activity of Aristolochia rotunda & its substitute, Curcuma Zedoaria in albino Wistar rats. METHODS: Physicochemical standardization by estimation of moisture content, ash values and extractive values were carried out using standard methods. Hepatotoxicity was induced in albino Wistar rats using CCl4 1 mL/kg s. c. on alternate day for 14 days. Group I was served as Plain control and Group II as Negative control. Group III was administered silymarin 50 mg/kg p. o. while Group IV received HAE of A. rotunda 89.64 mg/kg p. o., and Group V was administered HAE of C. Zedoaria 45.73 mg/kg p. o. At the end of the study, serum bilirubin, AST (SGOT), ALT (SGPT) and ALP were estimated. The histopathology of liver was also carried out. RESULTS: The physicochemical parameters of both test drugs viz. moisture content, total ash, acid insoluble ash and water soluble ash were found within normal limit. The total serum bilirubin, direct bilirubin, AST (SGOT), ALT (SGPT) levels were significantly decreased in Test groups A and B when compared to the Negative and Standard controls. The microscopic examination of liver collected from animals of Group IV and Group V revealed significant recovery from hepatic toxicity compared to the Negative control. CONCLUSIONS: The study experimentation has revealed that C. Zedoaria may be used as a substitute for A. rotunda in the treatment of liver diseases. However, the outcome has to be further corroborated with phytochemical evaluation and clinical trials of both the drugs. Furthermore, the concept of drug substitute in Unani system of medicine is also validated in the light of above study.

Ameliorative effects of Cuscuta reflexa and Peucedanum grande on letrozole induced polycystic ovary syndrome in Wistar rats.

OBJECTIVES: The current study was designed to examine the therapeutic role of hydroalcoholic extract of Cuscuta reflexa Roxb (CRE) and Peucedanum grande C.B. Clarke (PGE) on letrozole (1 mg/kg) induced polycystic ovary syndrome (PCOS) in female Wistar albino rats. METHODS: PCOS rats were treated with CRE (280 mg/kg), PGE (140 mg/kg) or CRE + PGE p.o. for 3 weeks. Vaginal smears for phase of estrous cycle determination, serum levels of sex androgens, lipid profile, oxidative stress parameters and histopathology of ovarian tissues were investigated. RESULTS: Diestrous cycle days treated with CRE (group III) or PGE (group IV) decreased significantly (p < 0.05) compared to PCOS control animals (group II). Moreover, weight of uteri in PCOS animals treated with the plant extracts also increased significantly (p < 0.05) compared to that of group II animals. Histopathological examination showed the protective effect of the CRE and PGE indicated by the disappearance of ovarian cyst. CONCLUSION: The study demonstrated that the CRE and PGE either alone or in combination hold a significant effect in letrozole induced PCOS rat models and could be useful in the management of reproductive and metabolic disorders related to PCOS.

Reactivity of tris(acetylacetonato) iron(III) with tridentate [ONO] donor Schiff base as an access to newer mixed-ligand iron(III) complexes.

Two new mixed-ligand iron(III) complexes, [Fe(L(n))(acac)(C(2)H(5)OH)] incorporating coordinated ethanol from the reaction solvent were accessed from the reaction of [Fe(acac)(3)] with [ONO] donor dibasic tridentate unsymmetrical Schiff base ligands derived from condensation of 2-hydroxy-1-napthaldehyde with 2-aminophenol (H(2)L(1)) or 2-aminobenzoic acid (H(2)L(2)). The thermal study (TGA-DTA) provided evidence for weakly bound ethanol which is readily substituted by neutral N-donor molecule imidazole, benzimidazole or pyridine to produce an array of newer complexes, [Fe(L(n))(acac)X] (n=1, 2; X=Im, Bim, Py). The compounds were characterized by elemental analyses, FT-IR, UV-vis, solution electrical conductivity, FAB mass, (1)H and (13)C NMR spectroscopy. Room temperature magnetic susceptibility measurements (µ(eff)∼5.8 B.M.) are consistent with spin-free octahedral iron(III) complexes. Cyclic voltammetry of ethanol complexes revealed a quasi-reversible one electron redox response (ΔE(p)>100 mV) for the Fe(III)/Fe(II) couple. Low half wave redox potential (E(1/2)) values suggested easy redox susceptibility. The ground state geometries of the ethanol and imidazole complexes have been ascertained to be distorted octahedral by density functional theory using DMol3 program at BLYP/DNP level.