A Note on the Thermodynamics of the Wet-and Dry-Bulb Hygrometer

The paper deals with the thermodynamic study of the wet-and-dry bulb hygrometer as applied to other liquids besides water. Hygroscopic liquids are also included. The theory is found in reasonable accord with experiment

Design Optimization and Evaluation of Gastric Floating Matrix Tablet of Glipizide

Purpose: To formulate an optimized gastric floating drug delivery system (GFDDS) containing glipizide with carbomers and cellulosic polymers.Method: Central composite design (CCD) was employed in formulating the GFDDS using hydroxypropyl methylcellulose K4M (HPMC K4M) (A) and Carbopol 934P (CP934P) (B), as independent variables. Floating lag time (FLT), total floating time (TFT) and time required to release 50 % of the drug (T50) were selected as dependent variables. The dissolution data obtained were fitted to various release models and the floating profiles of the formulations analyzed.Results: HPMC K4M loading clearly enhanced floating properties while CP934P showed negative effect on floating properties but was helpful in controlling drug release. The quadratic mathematical model developed was used to predict optimum formulations. The computer optimization process, contour plots and response surface plots predicted the concentration of independent variables A and B to be 47.32 and 8.4 mg, respectively, for maximum TFT and T50 at the same time for least FLT. Predicted concentration of independent variables showed the same results experimentally, with -0.75 - 1.47 percentage errors.Conclusion: CCD demonstrated the role of the derived equations, contour plots and response surface plots in predicting the values of independent variables for the preparation and optimization of glipizide gastric floating matrix tablet.Keywords: Effervescent, Floating tablet, Design of Experiment, Release kinetics, Central composite design, Optimization

Inverse Correlation between Insulin‑like Growth Factor‑1 and Leptin Levels in Preeclampsia

Background: Preeclampsia is the major cause of maternofetal and neonatal morbidity and mortality. Insulin‑like growth factor (IGF) system has a crucial role in correct embryonic and placental development and growth. Conflicting data are available regarding IGF‑1 in preeclamptic mothers. The extent to which leptin per se mediates the fetal growth and developmental abnormalities associated with preeclampsia remains to be clarified.Aim: Hence, the present study was planned to assess IGF‑1 and leptin levels in maternal and cord blood of preeclamptics and to compare them with normotensive pregnant women.Subjects and Methods: The present study was conducted in the Department of Biochemistry in collaboration with the Department of Obstetrics and Gynaecology, Pt. B.D. Sharma, PGIMS, Rohtak. Totally, 25 normotensive pregnant and 25 preeclamptic women were enrolled, and serum leptin and IGF‑1 levels were analyzed in maternal and cord blood of women by enzyme‑linked immunosorbent assay.Results: IGF‑I levels were lowered in maternal blood of preeclamptic as compared to normotensive mothers (P < 0.001). Leptin levels were significantly increased in preeclamptic mothers as compared to normotensive mothers (P < 0.001). Leptin had a positive correlation with IGF in both groups and it is highly statistically significant in preeclamptic mothers. Conclusion: Findings of the present study suggest that IGF‑1 and leptin play a central role in controlling fetal growth.KEY WORDS: Cord blood, insulin‑like growth factor‑1, leptin, preeclamptics, pregnanc

A remark on Gwinner's existence theorem on variational inequality problem

Gwinner (1981) proved an existence theorem for a variational inequality problem involving an upper semicontinuous multifunction with compact convex values. The aim of this paper is to solve this problem for a multifunction with open inverse values

Ising Ferromagnet: Zero-Temperature Dynamic Evolution

The dynamic evolution at zero temperature of a uniform Ising ferromagnet on a square lattice is followed by Monte Carlo computer simulations. The system always eventually reaches a final, absorbing state, which sometimes coincides with a ground state (all spins parallel), and sometimes does not (parallel stripes of spins up and down). We initiate here the numerical study of ``Chaotic Time Dependence'' (CTD) by seeing how much information about the final state is predictable from the randomly generated quenched initial state. CTD was originally proposed to explain how nonequilibrium spin glasses could manifest equilibrium pure state structure, but in simpler systems such as homogeneous ferromagnets it is closely related to long-term predictability and our results suggest that CTD might indeed occur in the infinite volume limit.Comment: 14 pages, Latex with 8 EPS figure

Structural and magnetic properties of the (001) and (111) surfaces of the half-metal NiMnSb

Using the full potential linearised augmented planewave method we study the electronic and magnetic properties of the (001) and (111) surfaces of the half-metallic Heusler alloy NiMnSb from first-principles. We take into account all possible surface terminations including relaxations of these surfaces. Special attention is paid to the spin-polarization at the Fermi level which governs the spin-injection from such a metal into a semiconductor. In general, these surfaces lose the half-metallic character of the bulk NiMnSb, but for the (111) surfaces this loss is more pronounced. Although structural optimization does not change these features qualitatively, specifically for the (111) surfaces relaxations can compensate much of the spin-polarization at the Fermi surface that has been lost upon formation of the surface.Comment: 18 pages, 8 figure