GABAergic influences on plus-maze behaviour in mice

Manipulations of GABA function have been found to produce highly variable effects in animal models of anxiety. In the present series, an ethological version of the murine elevated plus-maze was used to examine in detail the behavioural profiles of diazepam (1.5 mg/kg; positive control) and a range of GABA-related compounds: valproic acid (100-400 mg/kg), No-711 (1.25-10.0 mg/kg), muscimol (0.5-3.0 mg/kg), (+)bicuculline (4.0-8.0 mg/kg), picrotoxin (0.25-2.0 mg/kg), R(+)baclofen (0.375-3.0 mg/kg) and CGP 35348 (25-200 mg/kg). On both conventional and ethological indices, results confirmed the anxiolytic profile of diazepam under present test conditions, and revealed substantially similar effects for the GABA-T inhibitor, valproic acid (100-400 mg/kg), and the GABAA receptor agonist, muscimol (2 mg/kg). The GABA reuptake inhibitor, No-711, produced weak anxiolytic-like effects at low doses (1.25-2.5 mg/kg) but disrupted behaviour at the highest dose tested (10 mg/ kg). Although the GABAA receptor antagonists, (+)bicuculline and picrotoxin, produced changes indicative of anxiety enhancement, concomitant behavioural suppression was evident at high doses (8 mg/kg and 1-2 mg/kg, respectively). Further studies suggested that the effects observed with bicuculline may be mediated by an active metabolite, such as bicucine. In contrast to the effects of valproic acid and direct GABAA receptor manipulations, the GABAB receptor agonist, R(+) baclofen, non-specifically disrupted behaviour at the highest dose tested (3 mg/kg) while the GABAB receptor antagonist, CGP 35348, was inactive over the dose range studied. Although present data confirm the sensitivity of the plus-maze to agents which modify GABAA receptor function, further studies will be required in order more fully to characterize this relationship.     

Efficient query evaluation on probabilistic databases

We describe a framework for supporting arbitrarily complex SQL queries with “uncertain” predicates. The query semantics is based on a probabilistic model and the results are ranked, much like in Information Retrieval. Our main focus is query evaluation. We describe an optimization algorithm that can compute efficiently most queries. We show, however, that the data complexity of some queries is #P-complete, which implies that these queries do not admit any efficient evaluation methods. For these queries we describe both an approximation algorithm and a Monte-Carlo simulation algorithm.     

Humidity sensing properties of spray deposited Fe doped TiO2 thin film

In the present work,ferrite (Fe) doped TiO2 thin films with different volume percentage (vol％) were synthesized us-ing a spray pyrolysis technique.The effect of Fe doping on structural properties such as crystallite size,texture coefficient,mi-crostrain,dislocation densities etc.were evaluated from the X ray diffratometry (XRD) data.XRD data revealed a polycrystalline anatase TiO2 phase for sample synthesized up to 2 vol％ and mixed anatase and rutile crystalline phase for sample synthesized at 4 vol％ Fe doped TiO2.The crystalline size was observed to decrease with increase in Fe dopant vol％ and also other structur-al parameters changes with Fe dopant percentage.In the present work,electrical resistance was observed to decrease with a rise in Fe dopant vol％ and temperature of the sample.Thermal properties like temperature coefficient of resistance and activa-tion energy also showed strong correlation with Fe dopant vol％.Humidity sensing properties of the synthesized sample altered with a change in Fe dopant vol％.In the present paper,maximum sensitivity of about 88.7％ for the sample synthes-ized with 2 vol％ Fe doped TiO2 and also the lowest response and recovery time of about 52 and 3 s were reported for the same sample.     

Case study on energy audit in HPCL,Mazgaon Dock Ltd,Mumbai

ABSTRACT

The paper comprises Energy Audit of Mechanical Equipment in HPCL (Hindustan Petroleum Corporation Limited), Mazgaon Dock, Mumbai. It represents the energy audit of counter-flow-type-induced draft cooling tower and other mechanical equipment. The technical data have been taken from Paharpur cooling tower (series 3800) HPCL, Mazgaon. Lube Plant 1 Cooling towers are generally heat-removal devices for industrial processes as well as for for chemical plants. The present review is aimed at study and research on the cooling tower for increasing the efficiency and power savings to make it more economical and efficient. Using boiler of high efficiency helps in reducing the cost which is an important factor in industries and to reduce the emissions. The direct efficiency method can be used but it does not focus on energy losses so the standard methods are used. But the modified Siegert’s equation is a very common equation for finding out the boiler efficiency.     

Modeling and validation of heat transfer in packed bed with internal heat generation

Several researchers have modeled the heat transfer in a packed bed, heated externally, and determined its effective thermal conductivity ( $k_{\mathit{eff}}$). But till date, very few researchers have studied the heat transfer of the pebble bed, where the heat is generated inside the bed; and the effective thermal conductivity of the packed bed with internal heat generation has not yet been reported. In the present work, heat generation inside the bed has been imitated by inductively heating randomly placed steel balls with lithium titanate ( ${\text{Li}}_2{\text{TiO}}_3$) pebbles. The system has been modeled and validated with experimental results. The $k_{\mathit{eff}}$ of the ${\text{Li}}_2{\text{TiO}}_3$ pebble bed is determined for various process conditions. A correlation has been developed to calculate the $k_{\mathit{eff}}$ based on various process parameters such as pebble diameter, air flow rate, and induction temperature. The result presented in this study will be used for the design and scale‐up studies of future fusion reactors.     

Transabdominal extensive oesophagogastric devascularization with gastro-oesophageal stapling in the management of acute variceal bleeding

BACKGROUND: Operation is required for patients with portal hypertension who have failed to respond to emergency sclerotherapy for control of acute variceal bleeding. This study evaluates the role of transabdominal extensive oesophagogastric devascularization combined with gastro-oesophageal stapling for control of acute variceal bleeding in patients with portal hypertension of different aetiologies. METHODS: Transabdominal extensive oesophagogastric devascularization combined with gastrooesophageal stapling was performed in 65 patients (28 with cirrhosis, 17 with non-cirrhotic portal fibrosis and 20 with extrahepatic portal venous obstruction) in whom emergency endoscopic sclerotherapy, and/or pharmacotherapy and balloon tamponade had failed. The Sugiura procedure was modified to minimize operating time and to reduce the operative difficulties due to oesophageal wall necrosis after sclerotherapy. RESULTS: The operative mortality rate was higher in patients with cirrhosis (P = 0.0003); sepsis was the leading cause of death (in nine of 18). A high mortality rate (12 of 15) was seen in patients with Child grade C cirrhosis. Control of bleeding was achieved in all patients. The procedure-related complication rate was 17 per cent with a 6 per cent oesophageal leak rate; four of 47 surviving patients developed oesophageal stricture. During a mean follow-up of 33 months, residual varices, recurrent varices and rebleeding were seen in three, two and three of 47 survivors. CONCLUSION: Transabdominal extensive oesophagogastric devascularization combined with gastrooesophageal stapling is an effective and safe procedure for control of acute variceal haemorrhage with satisfactory long-term control, especially in patients without cirrhosis and low-risk patients with cirrhosis.     

Green Synthesis of Silver Nanoparticles Using Salacia chinensis: Characterization and its Antibacterial Activity

The aim of the present research work was to synthesize silver nanoparticles (AgNPs) using Salacia chinensis plant extract and to evaluate its antibacterial activity. AgNPs were successfully synthesized and formation of AgNPs was confirmed by visual color change and UV (ultraviolet) spectroscopy. Prepared AgNPs were purified and characterized by using dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM-EDAX), and transmission electron microscopy (TEM). UV peak at 434 nm confirmed the formation of AgNPs. DLS studies showed that AgNPs size prepared in all conditions were in the range of 100–200 nm. XRD studies revealed crystalline nature of AgNPs. EDAX studies confirmed the presence of silver in colloidal dispersion and images were recorded by using SEM and TEM. Synthesized AgNPs were found to be effective against Staphylococcus aureus and Pseudomonas aeruginosa. In conclusion, AgNPs could serve as a good alternative in treatment of bacterial infections in this era of multidrug resistance.     

Processing and properties of Y-TZP/Al2O3 composites

The processing and property measurement of Y-TZP/Al₂O₃ ceramic-ceramic composites was investigated. The wet chemical synthesis route was adopted for the preparation of 3Y-TZP matrix dispersed with Al₂O₃ in three different volume fractions. Characterization of the resultant powders was carried out and their densification behaviour was studied by sintering in air in the temperature range 1200–1600 °C. The role of alumina as grain-growth inhibitor for Y-TZP, and the mechanical response of these ultrafine-grain ceramic composites in terms of K_lc characteristics, have been discussed.     

Mass and heat transfer analysis of SAS: effects of thermodynamic states and flow rates on droplet size

The supercritical antisolvent (SAS) process entails attainment of extremely high supersaturation in an atomized solution droplet by a very rapid increase in the antisolvent CO₂ mole fraction in it during its flight through a CO₂ continuum. In this work the droplet dynamics has been studied for a single droplet of CO₂–acetone solution falling in a flowing CO₂ environment in terms of variations in its concentration, temperature and size due to the two-way mass transfer of CO₂ and solvent. A model based on the SAS mechanism of simultaneous mass and heat transfer has been simulated to study the effects of the thermodynamic states and the individual flow rates of CO₂ and solution. The hydrodynamics of the droplet and the convective mass and heat transfer have been combined in the model to ascertain the individual number of moles of CO₂ and solvent transferred and their directions at any instant of time during the flight. The effects of process parameters have been analyzed for the initial droplet size of the solution. The swelling or shrinking of the droplet has been analyzed with time till the solvent is completely evaporated, in the pressure range of 71–350 bar, temperature range of 313–333 K, SC CO₂ flow rate of 0.1136–1.136 mol/s and the ratio of the volumetric flow rates of CO₂-to-solution in the range of 100–1000. The mole fraction of CO₂ attained inside the non-isothermal droplet has been analyzed with time, which is needed in the design of supersaturaton and nucleation kinetics in the SAS process.