APPLICATION OF NANOSILVER FOR PREVENTION OF RECURRENT DENTAL CARIES IN PATIENTS SUFFERING FROM XEROSTOMIA.

Objective: Prevention of recurrent caries due to decreased oral clearance and an abnormal microbial milieu in patients suffering from xerostomia poses a significant challenge in restorative dentistry. The present study was designed to control Gram negative bacilli and S. aureus which comprise a majority of such atypical populations by using nanosilver modified dental composite. Methods: Silver nanoparticles were synthesised by the chemical reduction process using polyvinyl pyrrolidone as a stabilizer and ethylene glycol as the reducing agent. Nanoparticles were characterized using UV visible spectroscopy and a scanning electron microscope equipped with an energy dispersive X-ray analyser. Additionally a nanoparticle analyzer was used to determine the particle size and zeta potential of the nanosilver synthesized. The minimum inhibitory concentration of nanosilver for the test organisms was determined. Further, nanoparticle impregnated Anterior/ Posterior Nano-Hybrid composite was used to evaluate microbial biofilm inhibition. Results: The average size and charge of the nanoparticles were confirmed to be 80 nm and -10mV respectively. Atomic absorption spectroscopy revealed the concentration of the nanoparticles in solution to be 998.5 ppm. The minimum inhibitory concentration of nanosilver for E. coli and Ps. aeruginosa was found to be 0.49 ppm and 0.975 ppm respectively. A slightly higher concentration of 1.95 ppm nanosilver was required to inhibit S. aureus. The minimum bactericidal concentration/minimum inhibitory concentration ratio was ≤4 which indicated that nanoparticles displayed a predominant bactericidal activity against the test organisms. The Nano-Hybrid composite studies demonstrated a 102to105 fold decrease in the viable count of bacteria as compared to the control. Conclusion: To our knowledge, this is the first study to demonstrate the potential of silver nanoparticles, for controlling the formation of secondary dental caries due to pathogenic oropharyngeal colonization in patients suffering from xerostomia

Evaluating the linkages between technological strategies and competitive strategies of business units in different technological environments : a U.S./Canada contrast.

The links between technological and competitive strategies of business units (BUs) trying to achieve a competitive edge in the market have recently drawn a considerable amount of attention. Current research recognizes the strategic nature of technology itself and suggests that business managers have to understand their technological environments before they can gain any substantial competitive advantage. This study provides a structural framework for empirical research into the relationship between a business unit\u27s technological strategy and its competitive strategy, in the context of its technological environment. Using the Profit Impact of Market Strategy (PIMS) Data Base, a sample of 3,336 business units in the U.S. and Canada are cross-classified into stable, fertile and turbulent technological environments and by the three stages (growth, mature and decline) of their product life-cycle. Analysis of variance is applied to a set of variables in an exploratory attempt to determine response patterns of five Technological Strategy variables (dependent variables) in each of six Strategic Configurations (independent variables). The research attempts to examine the links that emerge between Technological Strategy and Competitive Strategy variables, in the context of BUs\u27 technological environment and stage of product life-cycle. The sample is divided into U.S. and Canadian business units to explore any significant differences in competitive positioning between the two countries

The first definitive Middle Jurassic atoposaurid (Crocodylomorpha, Neosuchia), and a discussion on the genus Theriosuchus

Atoposaurids were a clade of semiaquatic crocodyliforms known from the Late Jurassic to the latest Cretaceous. Tentative remains from Europe, Morocco, and Madagascar may extend their range into the Middle Jurassic. Here we report the first unambiguous Middle Jurassic (late Bajocian–Bathonian) atoposaurid: an anterior dentary from the Isle of Skye, Scotland, UK. A comprehensive review of atoposaurid specimens demonstrates that this dentary can be referred to Theriosuchus based on several derived characters, and differs from the five previously recognized species within this genus. Despite several diagnostic features, we conservatively refer it to Theriosuchus sp., pending the discovery of more complete material. As the oldest known definitively diagnostic atoposaurid, this discovery indicates that the oldest members of this group were small-bodied, had heterodont dentition, and were most likely widespread components of European faunas. Our review of mandibular and dental features in atoposaurids not only allows us to present a revised diagnosis of Theriosuchus, but also reveals a great amount of variability within this genus, and indicates that there are currently five valid species that can be differentiated by unique combinations of dental characteristics. This variability can be included in future broad-scale cladistics analyses of atoposaurids and closely related crocodyliforms, which promise to help untangle the complicated taxonomy and evolutionary history of Atoposauridae

The Effect of Technological Environment and Competitive Strategy on Licensing Decisions

The expectation that firms that have a high differentiation strategy will also have low levels of licensing is not supported. For business units (BU) with products in the growth stages, the competitive strategy of the BU did not significantly affect licensing decisions. The results are not too surprising when one considers new technological advancements and global competition. A company may perceive its technological advantage as transitory and expect rapid imitation by competitors. In such a case, the company might want to license the innovation as quickly as possible to gain global acceptance. It is shown that when products mature, the competitive strategy dimensions do have a significant impact on licensing decisions. Under such conditions, the expectation that high differentiation will lead to protective actions was not confirmed. It is also shown that licensing activity is only related to the competitive strategy of the firm when the product-demand life cycle is in the mature stages

Research on the mechanism for removal of soluble BOD5 in clarifier systems. First pilot scale trial. Project 3216, EPA Ref. No. R 803-119-01, report three: a progress report to members of the Institute of Paper Chemistry

"EPA Ref. No. R 803-119-01.""August 18, 1975.""The Institute of Paper Chemistry, George A. Dubey, Averill J. Wiley, and Hardev S. Dugal, director, Division of Industrial and Environmental Systems.

Color removal in a ferric chloride-lime system

"November, 1975.

PHIL photoinjector test line

LAL is now equiped with its own platform for photoinjectors tests and Research and Developement, named PHIL (PHotoInjectors at LAL). This facility has two main purposes: push the limits of the photoinjectors performances working on both the design and the associated technology and provide a low energy (MeV) short pulses (ps) electron beam for the interested users. Another very important goal of this machine will be to provide an opportunity to form accelerator physics students, working in a high technology environment. To achieve this goal a test line was realised equipped with an RF source, magnets and beam diagnostics. In this article we will desrcibe the PHIL beamline and its characteristics together with the description of the first two photoinjector realised in LAL and tested: the ALPHAX and the PHIN RF Guns

Trueness of CAD/CAM digitization with a desktop scanner – an in vitro study

Desktop scanners are devices for digitization of conventional impressions or gypsum casts by indirect Computer-Aided Design/Computer-Assisted Manufacturing (CAD/CAM) in dentistry. The purpose of this in vitro study was: 1, to investigate whether virtual models produced by the extraoral scanner have the same trueness as sectioned casts; and 2, to assess if digitization with an extraoral scanner influences the surface information