Deep brain transcranial magnetic stimulation using variable “Halo coil” system

Transcranial Magnetic Stimulation has the potential to treat various neurological disorders non-invasively and safely. The “Halo coil” configuration can stimulate deeper regions of the brainwith lower surface to deep-brain field ratio compared to other coil configurations. The existing “Halo coil” configuration is fixed and is limited in varying the site of stimulation in the brain. We have developed a new system based on the current “Halo coil” design along with a graphicaluser interface system that enables the larger coil to rotate along the transverse plane. The new system can also enable vertical movement of larger coil. Thus, this adjustable “Halo coil” configuration can stimulate different regions of the brain by adjusting the position and orientation of the larger coil on the head. We have calculated magnetic and electric fields inside a MRI-derived heterogeneous head model for various positions and orientations of the coil. We have also investigated the mechanical and thermal stability of the adjustable “Halo coil” configuration for various positions and orientations of the coil to ensure safe operation of the system

Synthesis of Al and Ag nanoparticles through ultra-sonic dissociation of thermal evaporation deposited thin films for promising clinical applications as polymer nanocomposite

Nanoparticles (NPs) having well-defined shape, size and clean surface serve as ideal model system to investigate surface/interfacial reactions. Ag and Al NPs are receiving great interest due to their wide applications in bio-medical field, aerospace and space technology as combustible additives in propellants and hydrogen generation. Hence, in this study, we have synthesized Ag and Al NPs using an innovative approach of ultra-sonic dissociation of thin films. Phase and particle size distributions of the Ag and Al NPs have been determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thin film dissociation/dissolution mechanism, hence conversion into NPs has been characterized by SEM- scanning electron microscope. EDXA & ICPMS have been performed for chemical analysis of NPs. Optical properties have been characterized by UV-Vis and PL spectroscopy. These NPs have also been investigated for their anti-bacterial activity against Escherichia coli bacteria. To the best of our knowledge, this is the first time when NPs has been synthesized by ultra-sonic dissociation of thin films. As an application, these NPs were used further for synthesis of nanocomposite polymer membranes, which show excellent activity against bio film formation

Minimization of Volumetric Errors in CAD Medical Models Using 64 Slice Spiral CT Scanner

Sixty four slice spiral Computed Tomography (CT) scanner is one of the advanced CT scanners to capture the large volume of tissues and improved longitudinal resolution. The CT images are used to develop a 3-Dimensional (3D) Computer Aided Design (CAD) medical model. While developing a 3D CAD medical model volumetric errors occur due to partial volume or volume averaging effect. In order to study, various CT image construction parameters were considered to minimize the volumetric errors in 3D CAD medical models, a human dry mandible has been selected as a phantom. A Taguchi technique was used to find optimal CT image construction parameters. A L9 orthogonal array was used to optimize the CT image construction parameters constituting slice thickness, slice increment and Field of View (FOV) while performing CT image construction. The resultant optimal parameters are scrutinized using analysis of variance (ANOVA) method for its influence on the CT image construction. In this work, it has been found that there is a volumetric error of a 3D CAD medical model (STL file) from CT images of a dry mandible was 1978 mm3 (6.11%).Mechanical Engineerin

Bispectrum and Nonlinear Biasing of Galaxies: Perturbation Analysis, Numerical Simulation and SDSS Galaxy Clustering

We consider nonlinear biasing models of galaxies with particular attention to a correlation between linear and quadratic biasing coefficients, b_1 and b_2. We first derive perturbative expressions for b_1 and b_2 in halo and peak biasing models. Then we compute power spectra and bispectra of dark matter particles and halos using N-body simulation data and of volume-limited subsamples of Sloan Digital Sky Survey (SDSS) galaxies, and determine their b_1 and b_2. We find that the values of those coefficients at linear regimes (k<0.2h/Mpc) are fairly insensitive to the redshift-space distortion and the survey volume shape. The resulting normalized amplitudes of bispectra, Q, for equilateral triangles, are insensitive to the values of b_1 implying that b_2 indeed correlates with b_1. The present results explain the previous finding of Kayo et al. (2004) for the hierarchical relation of three-point correlation functions of SDSS galaxies. While the relations between b_1 and b_2 are quantitatively different for specific biasing models, their approximately similar correlations indicate a fairly generic outcome of the biasing due to the gravity in primordial Gaussian density fields.Comment: 14 pages, 8 figures, accepted for publication in PAS

Experimental Investigation of Process Parameters on 64 Slice Spiral CT Scanner of Medical Models

Rapid Prototyping (RP) is one of the advanced manufacturing methods to develop medical models. These models are generated by 3-Dimensional (3D) Computer Aided Design (CAD) model using Computed Tomography (CT) images. One of the advanced CT scanners to capture the large volume of tissues in shorter scan time is 64 slice spiral CT scanner. While developing these medical models, dimensional and volumetric errors occur due to Beam Hardening (BH) effect. This work has led to explore the influence of various CT Image acquisition parameters on the dimensional and volumetric errors, which are evaluated experimentally. A L9 orthogonal array and signal to noise ratio are applied to study performance characteristics of CT image acquisition parameters like tube voltage, tube current and pitch. The experimental results are analyzed by using the analysis of variance (ANOVA) method and significant factors are identified. In this work, it has been concluded that there is a reduction of dimensional error from 1.43 mm to 0.52 mm and volumetric error from 6793 mm3 to 3892 mm3.Mechanical Engineerin

Dynamic crossover scaling in polymer solutions

The crossover region in the phase diagram of polymer solutions, in the regime above the overlap concentration, is explored by Brownian Dynamics simulations, to map out the universal crossover scaling functions for the gyration radius and the single-chain diffusion constant. Scaling considerations, our simulation results, and recently reported data on the polymer contribution to the viscosity obtained from rheological measurements on DNA systems, support the assumption that there are simple relations between these functions, such that they can be inferred from one another.Comment: 4 pages, 6 figures, 1 Table. Revised version to appear in Physical Review Letters. Includes supplemental material

NOVEL CHRONOTHERAPEUTIC MULTIPARTICULATE DRUG DELIVERY SYSTEM OF FELODIPINE: AN EFFECTIVE TREATMENT FOR CARDIAC ARRHYTHMIA

Arrhythmia follows chronobiology, thus necessitating development of time-dependent formulation for its treatment. The aim of the current work was to develop a solubility-enhanced chronotherapeutic system of felodipine, a widely prescribed anti-arrhythmic. Systematically optimized hot-melt extrusion process was employed to formulate solubility-enhanced extrudates. Film-casting method was adopted for the selection of polymers. Drug released at 5, 15, 30min was taken as response variables in 32 face-centered cube design. Nearly 10-fold increase was observed in the solubility of the optimized extrudates in comparison to pure drug. Physical characterization of the extrudates depicted complete amorphization of drug. Sequential coating was performed on to the extrudates to enable a time-dependent release. In-vitro studies clearly demonstrated that 25% of drug was available rapidly within 10 min of administration. The remaining 75% of drug was available over a period of 4, 8 and 12h. Stability studies performed for 6 months at accelerated conditions depicted no significant change in the physicochemical characteristics of the optimized formulation. In-vivo pharmacokinetic studies conducted in beagle dogs ratified the results of in-vitro studies where a sequential time dependent absorption of felodipine was observed over a period of 12h. Concisely, the studies demonstrated successful development of solubility-enhanced chronotherapeutic system of felodipine

Leadership Practices, Competitive Priorities, and Manufacturing Group Performance

Purpose – The purpose of this paper is to examine the role of manufacturing leadership in enhancing manufacturing performance for different manufacturing configurations. Design/methodology/approach – Survey data collected from three levels of respondents in excess of 480, from 98 manufacturing units in the USA are used to test the study hypothesis using the cluster analysis and regression models. Findings – Effective leadership is positively associated with overall manufacturing performance beyond the fixed effects of organizational variables, such as competitive orientation and industry membership. The manufacturing leadership, however, does not seem to affect customer satisfaction. Research limitations/implications – The paper illustrates the use of behavioral theory of leadership in the context of managing operations with varying competitive orientations in different industries. Future research should, however, attempt to match different leadership practices/styles to different competitive orientations, and include employee characteristics, such as subordinates\u27 prior experience, training, or skills that may influence the need for demonstrating the leadership practices differently for different competitive orientations. Practical implications – As manufacturers pursue a combination of priorities, their manufacturing managers need to use a gamut of effective leadership practices, such as planning, delegating, inspiring, etc. Manufacturers may also note that effective manufacturing leadership enhances performance on a host of measures, such as quality, timeliness, efficiency, etc. which are directly influenced by the manufacturing group. For measures, such as customer satisfaction, manufacturing leadership needs to be augmented by managing customer expectations and by being more flexible in accommodating customers\u27 requirements. Originality/value – This is the first study to deploy multiple respondents to simultaneously examine the effects of competitive orientation and leadership practices on manufacturing performance