Investigation of heat-acid induced coagulation behaviour of whole milk systems employing front-face fluorescence spectroscopy

The heat-acid-induced coagulation behaviour of whole milk system (buffalo, cow and mixed milk) was studied by steady-state fluorescence spectroscopy exploiting tryptophan as a marker molecule. The varied molecular environment of tryptophan residues in the raw milk systems exerted different fluorescence properties. During the coagulation process, cow milk exhibited significant quenching and bathochromic shift in the emission spectra which was attributed to the low buffering ability and high hydration capacity of cow milk caseins. The results indicated that tryptophan residues of cow milk experienced more dynamic environment throughout the reaction as compared to buffalo milk

Study of phenol biodegradation by an indigenous mixed consortium of bacteria

227-233The potential of a mixed consortium of bacteria has been isolated from the soil of the East Calcutta Wetlands, the major waste treatment and recovery site of Kolkata, for degradation of phenol, a representative of phenolic compounds has been investigated. The mixed culture is first acclimatized to higher phenol concentrations in the mineral salt (MS) media and then its behaviour for degradation of phenol has been studied. The mixed culture successfully degrades phenol till 200 mg/L and then undergoes substrate inhibition at 400 mg/L. At still higher phenol concentration of 800 mg/L this mixed culture shows an anomalous behaviour by degrading phenol at a higher rate as compared to lesser phenol concentration by overcoming the substrate inhibition effect. The bacterial growth curve also follows the same pattern which indicates the observation. By the kinetic modeling of the substrate inhibition biokinetic constants are calculated which conform to experimentally observed values. For the phenol degradation and growth studies, Haldane model and Yano and Koga model are found to be the most efficient kinetic models respectively

Efficacy of lesion sterilization and tissue repair in primary tooth with internal resorption: A case series

Lesion sterilization and tissue repair (LSTR) treatment involves the use of a triple antibiotic mixture in a suitable vehicle, which is used to disinfect root canal systems. This report highlights three cases where LSTR therapy using triple antibiotic paste was attempted in primary molars exhibiting gross periradicular pathosis and internal resorption. Follow-up examinations revealed reduction of periradicular pathosis and reversal of internal resorption in all the three cases. This case series opens a perspective on the use of LSTR therapy as an alternative option to extraction in treating primary teeth with gross periradicular pathosis and internal resorption

Predicting the dental implant stability based on the antiresonance phase of a piezo-based impedance sensor

Background: The stability of dental implants (DIs) in in vivo tests can be determined using noninvasive resonance frequency analysis technique. A low-cost piezo-based sensor has been developed for this purpose which uses a readily available two-terminal piezo element, to which a metal substrate is adhesively glued for attaching the implant. Aim: The attainment of implant stability in dynamic tests using this sensor must be standardized in terms of the major antiresonance (AR) in the impedance phase responses using sensor-DI assembly. This will be used to predetermine the dimensions of the glued metal substrate in the sensor design. Materials and Methods: Multiple sensors with varying sensor dimensions were developed. Static and dynamic impedance studies were performed on these and corresponding sensor-implant assemblies. Static tests as well as in vitro tests with the sensor-implant assembly dipped in a standardized dental plaster mixture were performed in controlled laboratory conditions. Results: The probability of acceptance of the hypothesis has been checked using binomial distribution with a significance level of 5%. Statistically observed that for 95% of the cases where the DI becomes stable in dental plaster, both AR phase and AR frequency (ARF) return to their corresponding static values. Furthermore, for a piezo element, whose ARF is within 6–6.6 kHz, the sensor yields maximal phase when the length of the metallic strip is 2 cm. Conclusions: Experimental validation supports both claims. Hence, this work can be extended to in vivo DI stability determination and design aspects of the corresponding sensor

Performance Study of Chromium (VI) Removal in Presence of Phenol in a Continuous Packed Bed Reactor by Escherichia coli Isolated from East Calcutta Wetlands

Organic pollutants, like phenol, along with heavy metals, like chromium, are present in various industrial effluents that pose serious health hazard to humans. The present study looked at removal of chromium (VI) in presence of phenol in a counter-current continuous packed bed reactor packed with E. coli cells immobilized on clay chips. The cells removed 85% of 500 mg/L of chromium (VI) from MS media containing glucose. Glucose was then replaced by 500 mg/L phenol. Temperature and pH of the MS media prior to addition of phenol were 30 ∘ C and 7, respectively. Hydraulic retention times of phenol-and chromium (VI)-containing synthetic media and air flow rates were varied to study the removal efficiency of the reactor system. Then temperature conditions of the reactor system were varied from 10 ∘ C to 50 ∘ C, the optimum being 30 ∘ C. The pH of the media was varied from pH 1 to pH 12, and the optimum pH was found to be 7. The maximum removal efficiency of 77.7% was achieved for synthetic media containing phenol and chromium (VI) in the continuous reactor system at optimized conditions, namely, hydraulic retention time at 4.44 hr, air flow rate at 2.5 lpm, temperature at 30 ∘ C, and pH at 7

Can exposure to acidic beverages following the application of fluoride varnish cause changes in the amount of fluoride release? an in vitro study

Introduction: Fluoride varnishes are found to be effective in the prevention of early childhood caries. Postvarnish application, the instructions provided by the manufacturer seem to be inadequate because they do not mention the type of beverages which can be consumed after the specified time, considering the widespread consumption of soft acidic drinks in children. Aim: The study was conducted to evaluate the amount of fluoride released from fluoride varnishes − Fluorprotector and Bifluorid in artificial saliva and acidic conditions. Materials and Methods: Polymethyl methacrylate blocks were painted with fluoride varnish and placed into artificial saliva for 30 min. Blocks were then placed in either 1% citric acid or 0.3% citric acid solutions for 30 min with the solutions being replaced every 5 min. The solution was analyzed for fluoride content. Results and Conclusion: The statistical tests applied were repeated measures of analysis of variance and student’s t-test. The level of significance was kept at P < 0.05. Significant difference in fluoride release was noted in different acidic mediums. Fluoride release from fluoride varnishes varied considerably and also depended on the dissolution medium

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Not AvailableSoil lead (Pb) contamination by anthropogenic and industrial activities is a problemof global concern. In this research the possibility to adapt mid infrared-diffuse reflectance infrared Fourier transform spectroscopy (MIRDRIFTS) approach for the quantitative estimation of Pb in polluted soils was explored. One hundred soil samples were collected from an urban landfill agricultural site and scanned by MIR-DRIFTS. The raw reflectance spectra were preprocessed using four spectral transformations for predicting soil Pb contamination using three multivariate algorithms. Partial least squares regression using Savitzky–Golay (SG) first derivative spectra (RPD=3.05) outperformed principal component regression models. The artificial neural networks-SG model using an independent validation set produced satisfactory generalization capability (RPD = 2.01). Thus, the combination of MIR-DRIFTS and multivariate models can reduce chemical analysis frequency for soil pollution monitoring, substantially reducing labor and analytical cost.Not Availabl