Comparative Evaluation of Retention and Stability of Implant Supported Mandibular Overdenture using Locator attachment at Different Implant Positions: An In Vitro Study

AIM OF THE STUDY: The aim of this in-vitro study was to evaluate and compare the effect of different locations of implants on the retention and stability of two-implants supported overdenture with locator attachments. MATERIALS AND METHODOLOGY: An acrylic test specimen was fabricated with implants in four positions – A, B, D and E. Over that an acrylic test denture was constructed in the conventional way with vent holes for all the metal housings corresponding to the four implant positions. The same test denture was duplicated using autopolymerising resin to get the remaining samples. For group A, ten test dentures were fabricated with metal housings in B and D positions and the vent holes in A and E positions were sealed using autopolymerising resin. Similarly, for group B, ten test dentures were fabricated with metal housings in A and E positions and the vent holes in B and D positions were sealed using autopolymerising resin. To all the test dentures, four hooks were attached in canine and molar regions on both the sides and were subjected to tensile forces using Universal testing machine. Each test denture was subjected to three different tests. Test No. 1 was conducted to evaluate the effect of vertically directed dislodging forces. Test No. 2 was conducted to evaluate the effect of oblique rotational dislodging forces. Test No. 3 was conducted to evaluate the effect of posterior rotational dislodging forces. The force at which the denture detached from the specimen was recorded in Newton (N). Each test was repeated 5 times for each denture and the mean was obtained. RESULTS: Statistically significant difference (p value 0.032) was found with vertically directed dislodging forces with higher value seen in relation to group A. Highly Statistically significant difference (p value 0.00) was found with oblique rotational dislodging forces with higher value seen in relation to group B. Highly Statistically significant difference (p value 0.00) was found with posterior rotational dislodging forces with higher value seen in relation to group B. CONCLUSION: The results of the present study showed a significant difference between the two groups and thus rejected the null hypothesis

SYNTHESIS OF MESOPOROUS SILICA NANOPARTICLES AND DRUG LOADING FOR GRAM POSITIVE AND GRAM NEGATIVE BACTERIA

Objective: To synthesize mesoporous silica nanoparticles using the sol-gel method and to determine the antibacterial activity of mesoporous silica nanoparticles and tetracycline loaded mesoporous silica nanoparticles.Methods: In the synthetic procedure, the surfactant Cetyl Trimethyl Ammonium Bromide (CTAB) is initially dissolved in basic aqueous solution, and the mixture is vigorously stirred. Tetra Ethyl Ortho Silicate (TEOS) is added, and the solution is kept stirring for 6 h. After the reaction is complete, the as-synthesized product is filtered and washed with deionized water. The antibacterial was tested using disc diffusion method and minimum bactericidal concentration (MBC).Results: The synthesized mesoporous silica nanoparticles were characterized by using Scanning Electron Microscope (SEM) micrographs showed spherical particles with an average size of 350 nm. The powder X-Ray Diffraction (XRD) analysis of the material further confirmed the crystallinity of the mesopores as evidenced by the diffraction pattern of an intense peak at θ=24º. Fourier Transform Infra Red Spectroscopy (FTIR) indicated the involvement of carboxyl, amine and hydroxyl groups in the synthetic process. The result shows the inhibitory growth zone of 20 mm and 18 mm for tetracycline loaded mesoporous silica nanoparticles against Escherichia coli and Staphylococcus aureus respectively.Conclusion: To summarize, it has been experimentally demonstrated that mesoporous silica nanoparticle and tetracycline loaded mesoporous silica nanoparticles show very good antimicrobial behavior against the gram-positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria.Keywords: Mesoporous silica nanoparticles, Sol-gel method, Drug loading, Antibacterial activit

Corrosion and Quantum Studies of Alkyl Substituted Piperidin-4-Ones with Thiosemicarbazone on Mild Steel in an Acidic Medium

The acid corrosion inhibition technique of mild-steel in 1N sulfuric acid by a part of alkyl substituted 2,6-diphenyl piperidin-4-one with thiosemicarbazone has been observed by quantum chemical calculations, electrochemical AC impedance measurements, weight loss process and potentiodynamic polarization studies. Results show that substituted γ-2,c-6-diphenyl piperidin-4-ones with thiosemicarbazone act as perfect corrosion inhibitors and their inhibition efficiency increase with the addition of inhibitors. The potentiodynamic polarization curves pointed the studied inhibitors are mixed type of character and  cathodic nature in 1 N H2SO4 media. The impedance spectroscopy shows a change in the value of charge transfer resistance (Rct) and double layer capacitance (Cdl) indicating the adsorption of the some substituted piperidin-4-ones with thiosemicarbazones on the mild steel surface.   For all the three types of alkyl substituted 2,6-diphenyl pipieridin-4-one with thiosemicarbazone, the inhibition efficiency raised to increment in the inhibitor concentration and the performance of the three inhibitors are 01TS> 02TS> 03TS. The adsorption of the alkyl substituted 2,6-diphenyl piperidin-4-one with thiosemicarbazone on the mild-steel metallic surface pursued the Langmuir's adsorption isotherm. Quantum chemical calculations were executed by adopting density functional theory (DFT) to conclude whether a clear link exists among the inhibiting outcome of the inhibitor and the electronic characteristics of its main fundamentals

Fitted mesh method for singularly perturbed fourth order differential equation of convection diffusion type with integral boundary condition

This article focuses on a class of fourth-order singularly perturbed convection diffusion equations (SPCDE) with integral boundary conditions (IBC). A numerical method based on a finite difference scheme using Shishkin mesh is presented. The proposed method is close to the first-order convergent. The discrete norm yields an error estimate and theoretical estimations are tested by numerical experiments

Isolation of Marine Organisms and their Antifungal Studies

Marine organisms are a good source of new secondary metabolites that possess many biological activities including antibacterial, antifungal, anticancer, insecticidal and enzyme inhibition. Actinomycetes are known to produce bioactive substances, especially antibiotics that are effective against phytopathogenic fungi. Biocontrol with beneficial bacteria is one promising alternative to fungicides. Hydrolases such as chitinase contribute to degradation of fungal cell walls . Chitin is the second most abundant polysaccharide in nature and a major component of fungal walls, ,insect exoskeletons and crustacean shells.Chitinase secreted by a BCA is likely to be effective against pathogenic fungi, the cell walls of which are mainly Chitin. Several species have been isolated and screened from the soil in the past decades. Many of these secondary metabolites possess biological activities and have the potential to be developed as therapeutic agents. Bio-active compounds from marine organisms possess distinct chemical structures that are used in the synthesis of new drugs that could be used against pathogens. In this paper isolation of marine organism samples are collected at different marine environments and habitats and their antifungal studies are described

A COMPREHENSIVE STUDY ON TEXT INFORMATION EXTRACTION FROM NATURAL SCENE IMAGES

In Text Information Extraction (TIE) process, the text regions are localized and extracted from the images. It is an active research problem in computer vision applications. Diversity in text is due to the differences in size, style, orientation, alignment of text, low image contrast and complex backgrounds. The semantic information provided by an image can be used in different applications such as content based image retrieval, sign board identification etc. Text information extraction comprises of text image classification, text detection, localization, segmentation, enhancement and recognition. This paper contains a quick review on various text localization methods for localizing texts from natural scene images

Efficient cogeneration scheme for sugar industry

239-242Present work is a case study on sugar industry and economics is worked out for advanced cogeneration power system. By replacing low efficiency mill turbines with hydraulic drives and DC motors, cogeneration power increases in sugar mill to operate at high efficiency (65-70%). This replacement can aid increase of power to grid, resulting in additional revenue for sugar plant

Fatigue Spectrum for a Stiffened Composite Panel

A composite is a structural material that consists of two or more constituents that are combined at a macroscopic level and are not soluble in each other. One constituent is called the reinforcing phase and the one in which it is embedded is called the matrix. Such composites offer various advantages such as low weight, corrosion resistance, high fatigue strength, faster assembly etc and hence they are widely used in aircrafts. Various parts of the aircraft viz. wing, rudder, pressure bulkheads, fuselage skin and other minor parts. The study was on the testing of a stiffened panel, a component of the wing (Lower wing skin) of a transport aircraft. The objective of the study was to develop a standardized load sequence that would be a representative for the load-time history in the considered wing component. The load sequence was obtained through comparison of various transport aircrafts. A general spectrum was derived which was converted into a stepped spectrum for testing purposes. Flight blocks and flight types were defined for ease of programming and execution. The fatigue spectrum was derived based on a standardized spectrum published in literature and implemented in a computer program written in MATLAB computing environment

Studies on the genomic DNA integrity of marine fishes through chip-based gel electrophoresis

1695-1698Present study consists the extraction of gDNA from marine fish gut samples that belong to the Chaetodontidae family. Eppendorf BioSpectrometer kinetic, based on UV spectroscopy, and Qubit 2.0, was employed for this purpose, with ladder. Thus on-chip, gel electrophoresis was performed for the analysis of gDNA quantification and sizing in the NGS sample preparation workflow. Quantification of 2 different gDNAs from gut samples of Pakistan butterfly (Chaetodon collare) and Indian vagabond (Chaetodon decussates) was made with a standard DNA

Determination of the Region of Stabilizing Controller Parameters of Polytopic Polynomials

In the scenario of robust controller design for any given MIMO process system, control-designer faces real challenges in computing the optimum region of controller-parameters by following the conventional methodologies. Such methods are, in fact, much complex for analyzing and hence time consuming. In this paper, we employ the method of Kharitonov’s Theorem to determine the region for stabilizing controller-parameters (of polytypic polynomials). The main advantage of using this method is that it can be adopted or not only SISO, but also for MIMO system of any order; even if having perturbations in them. The Generalized Kharitonov Theorem given here provides a constructive solution to this problem by reducing it to the Hurwitz stability of a prescribed set of extremal line segments. The number of line segments in this test set is independent of the dimension of the parameter space. This test set has many important extremal properties that are useful in control systems