BIODEGRADABLE POLYMER: A NOVEL PHARMACEUTICAL CARRIER FOR SUSTAINED RELEASE OF METRONIDAZOLE

Objective: To optimize and evaluate the formulation of metronidazole (MT)-loaded chitosan microspheres and to investigate the efficiency of biodegradable polymer in developing sustained release formulation of MT to prolong the action of drug.Methods: MT microspheres were prepared using emulsion cross-linking method. Polymer-drug compatibility study was done using Fourier transform infrared. Physical characteristics were evaluated by particle size,SEM, flow properties etc. In vitro studies for evaluating drug release for MT-loaded chitosan microspheres were done by dissolution study.Results: Particle size of the formulated microspheres was found to be within the range of 110-130 μm. Flow properties of F1-F7 such as angle of repose, bulk density, and tapped density were found to be within limits. Drug entrapment efficiency was found to be better for all the formulations within the range of 74.82-84.32% w/w. Drug loading capacity was found to be in the range of 56-83.2% w/v. In vitro drug release was found to be in the range of 81.32-96.23% w/v.Conclusion: In spite of all the above results, we conclude that F5 formulation was optimized depending on the data obtained from the drug loading capacity and percentage drug release studies. F5 formulation is formulated with drug-polymer ratio 1:2 with 1% of di octyl sodium sulfo succinate and 8 ml of glutaraldehyde as a cross-linking agent

Effect of Vestibular Rehabilitation on Postural Stability in Children with Visual Impairment

Background and Aim: Postural stability is monitored by a circuitous system, particularly visual perception, vestibular apparatus, and somatosensory organs. The ability to maintain balance is significantly compromised in children with visual impairment and has higher risks of falls than the normal sighted children. Children with visual disability reported delayed motor dexterity such as eye-hand coordination, gross and fine motor controlinvolving struggle in gait procurement and postural control. Vestibular rehabilitation is the relevant therapy to restitute for maintaining postural control in the absence of visual information. This study aimed to find the effect of vestibular rehabilitation on postural stability in children with visual impairment. Methods: A quasi-experimental study was done in pre and post-test type design on 30 boys in the age group of 7-16 years’ children with visual impairment. Vestibular rehabilitation therapy was used as the exercise protocol to improve functional balance and reduction of falls in children with visual impairment for six weeks. Results: Statistical analysis was done between pre-test and post-test readings with SPSS 20 and there is a significant difference between the pre-test and post-test of total score and individual scores of Pediatric Balance Scale (PBS) after the intervention, since (p<0.05). Conclusion: Vestibular rehabilitation therapy improved the capability of postural controlling and reduces the risk of falls to an extent in children with visual impairment

Raman scattering investigation of electron-phonon coupling in carbon substituted MgB<SUB>2</SUB>

Room temperature Raman scattering measurements have been carried out on well characterized samples of MgB2-xCx. The Raman line corresponding to the E2g phonon mode shows progressive hardening from 620 cm&#8722;1 in pristine MgB2 to 775 cm&#8722;1 in the sample with carbon fraction x = 0.2. The corresponding line width on the other hand increases from a value of about 220 to 286 cm&#8722;1 in samples with x = 0.1, beyond which it decreases to a value of 167 cm&#8722;1 for x = 0.2. From the average mode frequency and the line width obtained from Raman measurements and taking the values of N(0) obtained from the calculated variation in &#963;-hole density of states in MgB2-xCx, the electron-phonon coupling strength to the E2g phonon, &#955;2g, is evaluated using Allen's formula. This remains large for low C fraction, but shows a rapid decrease for x&gt;0.10. Using this value of &#955;2gappropriately weighted, TC is obtained from McMillan's equation. These values are in good agreement with the experimentally measured TC variation in MgB2-xCx

The CRISPR/Cas9 System for Targeted Genome Engineering in Free-Living Fungi: Advances and Opportunities for Lichenized Fungi

Studies using whole genome sequencing, computational and gene expression, targeted genome engineering techniques for generating site-specific sequence alterations through non-homologous end joining (NHEJ) by genomic double-strand break (DSB) repair pathway with high precision, resulting in gene inactivation have elucidated the complexity of gene expression, and metabolic pathways in fungi. These tools and the data generated are crucial for precise generation of fungal products such as enzymes, secondary metabolites, antibiotics etc. Artificially engineered molecular scissors, zinc finger nucleases (ZFNs), Transcriptional activator-like effector nucleases (TALENs; that use protein motifs for DNA sequence recognition in the genome) and CRISPR associated protein 9 (Cas9;CRISPR/Cas9) system (RNA-DNA recognition) are being used in achieving targeted genome modifications for modifying traits in free-living fungal systems. Here, we discuss the recent research breakthroughs and developments which utilize CRISPR/Cas9 in the metabolic engineering of free-living fungi for the biosynthesis of secondary metabolites, enzyme production, antibiotics and to develop resistance against post-harvest browning of edible mushrooms and fungal pathogenesis. We also discuss the potential and advantages of using targeted genome engineering in lichenized fungal (mycobiont) cultures to enhance their growth and secondary metabolite production in vitro can be complemented by other molecular approaches

Drastic ground state changes induced by Ni substitution in NaxCoO2

We report on the effect of Ni substitution at the Co site on the physical properties of NaxCoO2 system by investigating the series NaxCo1-yNiyO2 (x=0.75, 0<y<0.15). An upturn in the resistivity is observed in all Ni substituted samples as the temperature is lowered, suggestive of the occurrence of a Metal-Insulator Transition (MIT). The temperature at which this transition occurs increases with Ni content. The temperature dependence of the resistivity in the metallic region in the Ni substituted samples shows a T2 dependence, which is qualitatively different from that observed in the pristine sample. The evolution of the Fano asymmetry parameter, extracted by analyzing the lineshape of the IR active in-plane Co-O mode, both as a function of Ni concentration and temperature corroborates the occurrence of the MIT. It is argued that the progressive substitution of the Co4+ ions with Ni increases the probability of double occupancy and therefore the on-site Coulomb interaction energy leading to a shift in the thermodynamically driven MIT to higher temperatures.Comment: 17 pages 9 figures; submitted to Journal Of Phys. Cond. Ma

Return and Volatility Spillovers of Asian Pacific Stock Markets’ Energy Indices

The aim of the study was to investigate the presence of volatility among the Energy Indices of Asia Pacific Stock Markets. To test the volatility among the daily returns of Energy Indices of Asia Pacific Stock Markets, the study selected five sample Asian Pacific stock markets’ Energy Indices on the basis of availability of data. The findings of descriptive statistics and the ADF Test revealed, that the daily returns of the sample energy indices of Asian Pacific stock markets were not normally distributed and achieved stationarity at level difference, over the research period. Hence the data may be used for additional analysis. The data were then analysed, by using the GARCH (1,1) model to assess the considerable volatility of daily returns of sample energy indices and the study, which revealed that during the study period, all of the sample energy indices were volatile

Expansions in the Non-Ideal Compressible Flow Regime: A Numerical and Experimental Study

Organic Rankine Cycle systems are gaining increasing attention as a modular, cost-effective and decentralised thermal energy recovery solution. The design of an efficient expander in the ORC system is crucial to its rapid uptake by the industry. Compared to volumetric expanders, a radial turbine provides advantages in terms of flexibility and better part-load performances. The design of ORC radial turbines is faced with two challenges. Firstly, the expansion in the stator occurs close to the vapour-liquid dome and the critical point, where the ideal gas assumption is no longer valid. Such expansions fall under the Non-ideal thermodynamic regime. Secondly, due to the lower speed of sound in the working fluid, the expansions are supersonic and are accompanied by compressible flow features such as shock waves, expansion fans which generate entropy and reduce the performance of the expander. There exists significant validated design methodologies and empirical relations for conventional turbomachinery. However this is not the case for unconventional turbomachinery where established loss correlations are not applicable. Hence, there is a knowledge gap in validated design tools for unconventional turbomachinery like ORC radial turbines. The thesis forms a part of the validation campaign of the open-source flow solver, SU2 and approaches the exercise by studying expansions in two paradigmatic test cases, namely (i) a linear stator cascade and (ii) a converging - diverging nozzle.The study of expansions through a linear cascade is a preceding step to the study of a rotating radial turbine. Consequently, a RANS simulation on the single channel blade passage is studied under the validated assumption of flow periodicity. The expansion takes place from inlet total conditions of 18.4 bara and 525 K (Z =0.558) to a static pressure of 1.95 bara (Z = 0.951) and exit flow of Mach 2. Two types of response quantities are studied namely direct and system response quantities. Direct response quantities are those that can be measured directly such as the pressure, Mach, density. System response quantities are derived from direct measurements and provide information to characterise the performance of the stator. The selected system response quantities are: (i) Pressure loss coefficient (Cp= 0.074), (ii) Kinetic energy loss coefficient (ζKE= 0.115), (iii) Entropy loss coefficient (ζs=0.118), (iv) Base pressure loss coefficient (Cpb= -0.065), (v) Standard deviation of exit flow angle (σβ2 = 1.244) and (vi) Standard deviation of exit Mach (σM2= 0.033). Experimentally, it is possible to measure the pressure loss coefficient, base pressure loss coefficient and the flow uniformity at the outlet using a combination of pressure and direct velocity measurements. Through a Design of Experiments approach, the sensitivity of the flow to input uncertainties was studied through a stochastic collocation based forward propagation of the uncertainty. The input uncertainties considered are the inlet total pressure, fluid viscosity and critical point properties. The Sobol indices from the uncertainty quantification indicate the more dominant influence of the critical point properties over other inputs considered. The results also validate the use of a constant viscosity assumption for the RANS simulation. The subsequent planned unit test case was to characterise the expansion through an optimised stator blade row. To this end, a deterministic adjoint based optimisation was performed with the objective function of minimising entropy generation. The resulting geometry was studied and resulted in a pressure loss coefficient improvement of around 4%, although stator flow uniformity at the exit was compromised. The uncertainty quantification performed on the optimised blade geometry yielded robustness improvements on the pressure loss coefficient and reduction in uncertainties associated with direct response quantities, although no strong correlations can be drawn between the improvements in uncertainty and the deterministic optimisation. Given current machining tolerances, the realisation of such a negligible geometry change is not viable from an experimentalperspective.The second section of the thesis deals with experimental investigation of expansions in a converging-diverging nozzle through a matrix of isobars with increasing degree on non-ideality. Two isentropes with inlet pressure of 2.73 bara (Z = 0.9526) and 6 bara (Z = 0.901) with pressure ratio of 8.76 were performed with recording of pressure, temperature, flowrate and density measurements along the ORCHID. The flow field was visualised using the schlieren method using a z-type layout. The thesis reports the first measurements of total pressure before the nozzle inlet and vapour density and flowrate measurements. The experimental data was post-processed to identify steady-state and quantify the Type A and Type B uncertainties. The schlieren images were used to extract information on the Mach distribution along the nozzle mid-plane using an inhouse line extraction tool. Lastly, a 2.5o wedge at the exit of the nozzle is used to generate oblique shock waves that are then manually measured. The flow field at the exit of the nozzle is in the ideal region where the shock angle only depends on upstream Mach number. Hence, the experimentally observed oblique shock angles for the off-design case are close to on-design (Inlet pressure = 18.4 bara) predictions

Evaluation of effect of core build-up materials on fracture resistance of endodontically treated teeth: Fracture resistance of core build-up materials

Background: Restoration of teeth after endodontic treatment is becoming an integral part of reconstructive dentistry. Aim: The aim of this study was to evaluate the effect of different core build-up materials on fracture resistance of endodontically treated teeth. Materials and methods: Freshly extracted forty permanent mandibular first molars were selected. Standardized access cavities were prepared, following which mesial canals were prepared up to F2 (8%25) and distal canals up to F3 (9%30) and obturated. The coronal portion of the specimen was altered by removing the mesial wall and retaining buccal, lingual and mesial walls of 2mm and distal 5mm girth. Ten specimens each were rehabilitated with high copper amalgam, type IX GIC, posterior composite and Alkasite as core build-ups. All the specimens were finally rehabilitated with a metal crown. The specimens were tested for fracture resistance using a universal testing machine under oblique (135o to the long axis of teeth) cyclic loading. The number of cycles taken to fracture and the fracture site was recorded. The results of mechanical cyclic loading to evaluate fracture resistance showed that composite core endured the maximum number of cycles to fracture followed by amalgam, Alkasite and type IX GIC. To test the statistical significance of the difference in mean value KIC among four groups, Kruskal-Wallis one-way analysis of variance was applied. Bonferroni’s multiple comparison test was performed to determine which group significantly differed from the others. Results: From the results of this study, the composite was considered to be the best core build-up material. The newer material, Alkasite can bear stress almost to that of amalgam restoration. Conclusion: This study suggests that Alkasite could be used as a core material for restoring the endodontically treated teeth