Antimicrobial efficacy of nanosilver, sodium hypochlorite and chlorhexidine gluconate against Enterococcus faecalis

The purpose of this study was to compare the antibacterial efficacy of nanosilver (NS), chlorhexidine gluconate (CHX) and sodium hypochlorite (NaOCl) against Enterococcus faecalis. Two tests of minimum inhibitory concentration (MIC) and zone of inhibition were carried out using NS, NaOCl and CHX. 70-fold concentration of NaOCl is required for the same antibacterial effect of NS. CHX precipitated in contact with the culture medium and was excluded from MIC test. The means and standard deviations of the zones of inhibition for 5.25% NaOCl, 0.33% NaOCl, 25 μg/ml NS, 50 μg/ml NS, 4000 μg/ml NS and 2% CHX were 12.16 ± 1.46, 6.91 ± 0.66, 10.00 ± 0.42, 12.00 ± 0.60, 13.33 ± 1.23 and 24.80 ± 1.11, respectively. Statistical analysis using ANOVA showed significant differences among groups (p < 0.001). A post hoc Tukey test revealed no significant differences between 5.25% NaOCl and 4000 μg/ml NS (p = 0.057). However, the zones of inhibition for 2% CHX were significantly larger than those seen around the filter papers saturated with undiluted NaOCl and NS (p < 0.001 for both). This study revealed that NS in a remarkably lower concentration would possess the same bactericidal effect as 5.25% NaOCl.Key words: Chlorhexidine gluconate, Enterococcus faecalis, nanosilver, sodium hypochlorite

Accuracy of working length determination with root ZX apex locator and radiography: An in vivo and ex vivo study

The purpose of this study was to clinically compare working length (WL) determination with root ZX apex locator and radiography, and then compare them with direct visualization method ex vivo. A total of 75 maxillary central and lateral incisors were selected. Working length determination was carried out using radiographic and electronic apex locator methods. Subsequently, the tooth under study was extracted and actual working length was determined directly under a stereomicroscope. Data were analyzed by Wilcoxon signed-rank, Spearman’s correlation coefficient and intra-class correlation tests. All the statistical analyses were set with a significance level of α = 0.05. The absolute measurement errors of the two methods were compared using Wilcoxon signed test, exhibiting no statistically significant difference in measurement errors between the two methods. Descriptive evaluation revealed that in 72% (n = 54) of the specimens, both methods had errors in the same direction and in 28% (n = 21) of the specimens, the two methods had errors in opposite directions. Intra-class correlation coefficient test demonstrated a high degree of agreement between the two methods. In conclusion, this study did not show any difference between radiography, root ZX and direct visualization in WL determination.Key words: Working length, electronic apex locator, root ZX, radiography

Review paper: Introduction of pediatric balance therapy in children with vestibular dysfunction: Review of indications, mechanisms, and key exercises

The vestibular system is important for the development of normal movement reactions, motion tolerance, and motor control for postural alignment, balance, and vision. A vestibular system that is damaged by disease or injury in childhood can have a major impact on a child's development. In addition, the emergence of vestibular lesions may also lead to cognitive deficits, including attention deficit. Despite the advances in testing and documentation of vestibular deficits in children, the vestibular problems continue to be an overlooked entity. Many children do not receive treatment that could significantly improve function and address the developmental delays caused by vestibular disorders. Vestibular rehabilitation therapy (VRT) has been defined as an effective modality for most individuals with disorders of the vestibular or central balance system disorders. The basis for the success of VRT is the use of existing neural mechanisms in the human brain for adaptation, plasticity, and compensation. The vestibular system cannot be considered as a separate entity ignoring other balance subsystems. Hence, a modified VRT program, named pediatric balance therapy with special modifications in exercises, was developed for children with vestibular disorders, in accordance to the whole balance system

Cutting tool tracking and recognition based on infrared and visual imaging systems using principal component analysis (PCA) and discrete wavelet transform (DWT) combined with neural networks

The implementation of computerised condition monitoring systems for the detection cutting tools’ correct installation and fault diagnosis is of a high importance in modern manufacturing industries. The primary function of a condition monitoring system is to check the existence of the tool before starting any machining process and ensure its health during operation. The aim of this study is to assess the detection of the existence of the tool in the spindle and its health (i.e. normal or broken) using infrared and vision systems as a non-contact methodology. The application of Principal Component Analysis (PCA) and Discrete Wavelet Transform (DWT) combined with neural networks are investigated using both types of data in order to establish an effective and reliable novel software program for tool tracking and health recognition. Infrared and visual cameras are used to locate and track the cutting tool during the machining process using a suitable analysis and image processing algorithms. The capabilities of PCA and Discrete Wavelet Transform (DWT) combined with neural networks are investigated in recognising the tool’s condition by comparing the characteristics of the tool to those of known conditions in the training set. The experimental results have shown high performance when using the infrared data in comparison to visual images for the selected image and signal processing algorithms

N-body simulations with generic non-Gaussian initial conditions I: Power Spectrum and halo mass function

We address the issue of setting up generic non-Gaussian initial conditions for N-body simulations. We consider inflationary-motivated primordial non-Gaussianity where the perturbations in the Bardeen potential are given by a dominant Gaussian part plus a non-Gaussian part specified by its bispectrum. The approach we explore here is suitable for any bispectrum, i.e. it does not have to be of the so-called separable or factorizable form. The procedure of generating a non-Gaussian field with a given bispectrum (and a given power spectrum for the Gaussian component) is not univocal, and care must be taken so that higher-order corrections do not leave a too large signature on the power spectrum. This is so far a limiting factor of our approach. We then run N-body simulations for the most popular inflationary-motivated non-Gaussian shapes. The halo mass function and the non-linear power spectrum agree with theoretical analytical approximations proposed in the literature, even if they were so far developed and tested only for a particular shape (the local one). We plan to make the simulations outputs available to the community via the non-Gaussian simulations comparison project web site http://icc.ub.edu/~liciaverde/NGSCP.html.Comment: 23 pages, 10 figure

Ecology, life history, and fisheries potential of the flathead lobster (Thenus orientalis) in the Arabian Gulf

This study, which included examination of the distribution and life history and a stock assessment of the flathead lobster (Thenus orientalis), is the first of its kind in the waters of Saudi Arabia in the Arabian Gulf, also known as the Persian Gulf. The flathead lobster is widely distributed in this region, although it is more abundant in the central and northern Arabian Gulf. Carapace lengths at 50% and 95% maturity are 59 and 65 mm for females and 58 and 71 mm for males. The fecundity of 4 berried females ranged from 26,000 to 76,000 eggs per spawning, and the fertilization rate exceeded 97%. Length-frequency data were consistent with just 2 cohorts, indicating that this species has a short life span and high growth coefficient (K=0.846 year(-1)). Large fishing boats (called dhows) accounted for more than 98% of the total landings. Estimates of natural mortality rates from use of generalized depletion models have high statistical precision and a magnitude compatible with short life history. In addition, abundance levels estimated with the depletion model are sufficient to support a sustainable small-scale fishery either as bycatch of shrimp trawlers or as a resource targeted with specialized gear. A targeted fishery for flathead lobster could be set during the off months of the shrimp trawl fishery (February-July), reducing interference with the reproduction cycle.info:eu-repo/semantics/publishedVersio

Implementation of a multilayer statistical physics model to interpret the adsorption of food dyes on a chitosan film

This paper reports the application of an advanced multilayer model to study the adsorption of food dyes FD&C blue No. 2, acid red 18, FD&C red No. 2, and FD&C yellow 5 from aqueous solutions with a chitosan film. These dyes' adsorption mechanisms were discussed and analyzed at 298–328 K and pH 4–7 via statistical physics calculations. Physicochemical parameters were utilized to explain the dye adsorption at the molecular scale. Modeling results showed dye aggregation phenomena where each functional group of chitosan film adsorbed several dye molecules simultaneously at different tested temperatures. Aqueous solution temperature reduced the dye adsorption capacities, attributed to the exothermic nature of dye removal. The chitosan film was more effective for the adsorption of dye FD&C yellow 5. The estimated adsorption energies for dye-chitosan film and dye-dye interactions confirmed an exothermic physisorption associated with van der Waals forces and hydrogen bonding. This study's results contributed to expanding the knowledge on the adsorption mechanisms of dye molecules using biopolymers like chitosan

From Cooper Pairs to Composite Bosons: A Generalized RPA Analysis of Collective Excitations

The evolution of the ground state and the excitation spectrum of the two and three dimensional attractive Hubbard model is studied as the system evolves from a Cooper pair regime for weak attraction to a composite boson regime for a strong attraction.Comment: 20 pages RevTex, 7 figures on reques