Effect Insulin on DNA Synthesis and Kinetic Parameters of Thymidine Kinase During Liver Regenaration

The effect of insulin on cell proliferation in vivo has been studied in hepatectomised streptozotocin- diabetic rats. The extent of cell proliferation in sham and hepatectomized- control, diabetic and insulin treated rats were monitored by determining DNA content and [3H]thymidine incorporation into DNA. The kinetic parameters of thymidine kinase a regulatory enzyme for DNA synthesis was also studied in these groups. The rate of DNA synthesis in liver of streptozotocin -diabetic rats was significantly higher 24 hrs post-hepatectomy compared to control and insulin treated diabetic groups. Kinetic studies of thymidine kinase revealed that there was no change in the Michaelis -Menten constant (Km) whereas maximum velocity (Vmax) was elevated in the diabetic hepatectomized groups compared to control and insulin treated hepatectomized groups. Thus our study elucidates the role of insulin in thymidine kinase activity and DNA synthesis.

Elastic Constants And Structural Parameters Of Selected Polycrystalline Ceramics By Ultrasonic Technique

The present work is an attempt to probe the elastic properties in some dielectric ceramics, by using ultrasonic pulse echo overlap technique. The base Ba6-xSm8+2xTi18O54 and Ca5Nb2TiO12 are very important dielectrics ceramics used for microwave communication as well as for substrate materials. Ultrasonic is one of the most widely used and powerful techniques to measure elastic properties of solids. The ultrasonic technique is nondestructive in nature and the measurements are relatively straightforward to perform. One unique advantantage of the ultrasonic technique is that both static and dynamic properties can be measured simultaneously. The velocity and attenuation coefficients of the ultrasonic waves propagating through a medium are related to the microscopic structure of the material and they provide valuable information about the structural changes in the system. Among the various ultrasonic techniques, the pulse echo overlap method is the most accurate and precise one. In the present case the decreased elastic properties of Cas-XMg,Nb2TiO12 and Cas-,ZnNb2TiO12 ceramics can be attributed to their mixture phases beyond x = 1. Moreover, the abrupt change in elastic properties observed for x >1 can also be correlated to the structural transformation of the materials from their phase pure form to mixture phases for higher extent of substitution of the concerned material . Ca4(ANb2Ti)012 (A = Mg, Zn) is the strongest compound with the maximum values for elastic properties . This could be due to the possible substitution of Mg/Zn ions with lesser radius [25] than Ca2+ in perovskite B-site of Ca(Cali4Nb2i4Tili4) O3 material to contribute more ordering and symmetry to the system [20]. All other compositions (x > 1) contain mixed-phases and for such mixed-phase samples, the mechanical properties are difficult to explain.

Studies on Modified Atmosphere Packaging of Pearl Spot (Etroplussuratensis) With Special Emphasis to Biochemical and Microbiological Parameters

A modified atmosphere may be defined as a packaging or storage of a perishable product in an atmosphere other than that of air. A modified atmosphere (MA) applies to food packaged products changes continuously throughout the storage period. The pearl spot (Etroplus suratensis) is an important brackish water fish belonging to the family Cichlidae. The present work was carried out to see the effect of modified atmosphere packaging on the shelf life fresh pearl spot stored in ice to extent the shelf life. The objectives of the present study are to study the suitability of Thermoformed Trays for modified atmosphere packaging, to standardize the most suitable gas mixture for modified atmosphere packaging pearl spot based on sensory evaluation, to find out the effect of modified atmosphere packaging in comparison to air packaging, to study the biochemical, microbiological, sensory and textural characteristics during storage, to study the safety concern regarding the Clostridium botulinum during modified atmosphere packaging, to find out the most suitable chemical quality indices for modified atmosphere stored pearl spot

Tailoring the Microwave Dielectric Properties of GdTiNb 1 _-xTa,O6 and Sm 1 _X Y,TiTa06 Ceramics

Microwave dielectric ceramics based on GdTiNb,-,.Ta,O6 and Sml _.,Y,TiTa06 have been prepared by conventional solid state method . The GdTiTaO6 and SmTiTaO6 have aeschenite structure with positive rr and GdTiNbO6 and YTiTaO6 have euxenite structure with negative rr. The rr of the ceramics has been tuned by preparing solid solution phases between the aeschynites and euxenites for a possible zero rr material . It is observed that GdTiNbt_YTa.,O6 undergoes a phase transition from aeschynite to euxenite when x=0.75 and in Sml-,YxTiTa06 for x= 0.73. The microwave dielectric properties change abruptly near the transition region . The rr value approaches zero near the phase transition region while the samples have poor sinterability and poor quality factor . The unloaded quality factor, dielectric constant and the sign of rr of the solid solution phases are found to depend on the average ionic radius of the rare earth ion in RE ,-5RE',TiTaO6. The boundary of the euxenite-aeschynite phase transition occurs at an average ( RE) ionic radius of 0.915 A in Sm,_, Y,.TiTaO6 solid solution phases

Meiobenthos of Cochin backwaters in relation to macrobenthos and environmental parameters

Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology

Highly conductive and transparent ZnO thin film using Chemical Spray Pyrolysis technique: Effect of doping and deposition parameters

In the present work we report the preparation details studies on ZnO thin films. ZnO thin films are prepared using cost effective deposition technique viz., Chemical Spray Pyrolysis (CSP). The method is very effective for large area preparation of the ZnO thin film. A new post-deposition process could also be developed to avoid the adsorption of oxygen that usually occurs after the spraying process i.e., while cooling. Studies were done by changing the various deposition parameters for optimizing the properties of ZnO thin film. Moreover, different methods of doping using various elements are also tried to enhance the conductivity and transparency of the film to make these suitable for various optoelectronic applications.

Seasonal and interannual variability of sea level and associated surface meteorological parameters at Cochin

This thesis entitled seasonal and interannual variability of sea level and associated surface meteorological parameters at cochin.The interesting aspect of studying sea level variability on different time scales can be attributed to the diversity of its applications.Study of tides could perhaps be the oldest branch of physical oceanography.The thesis is presented in seven chapters. The first chapter gives, apart from a general introduction, a survey of literature on sea level variability on different time scales - tidal, seasonal and interannual (geological scales excluded), with particular emphasis on the work carried out in the Indian waters. The second chapter is devoted to the study of observed tides at Cochin on seasonal and interannual time scales using hourly water level data for the period 1988-1993. The third chapter describes the long-term climatology of some important surface oceanographic and meteorological parameters (at Cochin) which are supposed to affect the sea level. The fourth chapter addresses the problem of seasonal forecasting of the meteorological and oceanographic parameters at Cochin using autoregressive, sinusoidal and exponentially weighted moving average techniques and testing their accuracy with the observed data for the period 1991-1993. The fifth chapter describes the seasonal cycles of sea level and the driving forces at 16 stations along the Indian subcontinent. It also addresses the observed interannual variability of sea level at 15 stations using available multi-annual data sets. The sixth chapter deals with the problem of coastal trapped waves between Cochin and Beypore off the Kerala coast using sea level and atmospheric pressure data sets for the year 1977. The seventh and the last chapter contains the summary and conclusions and future outlook based on this study.