Publications by authors named "Blunt L"

Article Synopsis
  • This study investigates how different ratios of excipients like lactose, microcrystalline cellulose, and dicalcium phosphate affect the swelling and drug release of propranolol hydrochloride (PPN) from polyethylene oxide (PEO) matrix compacts.
  • The researchers used microscopy to analyze the compact surfaces and conducted dissolution studies to assess how the excipient ratios influenced hydration rates and drug release dynamics.
  • Findings indicate that modifying the amount of PEO and the type or ratio of excipients can significantly affect drug release rates, highlighting the innovative use of UV dissolution imaging for optimizing formulations.
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Many methods of ballistic toolmark comparison rely upon comparison using 2D greyscale imaging. However, newly emerging analysis methods such as areal surface analysis now utilise an extra dimension of measurement allowing the surface heights/depths of unique toolmark features to be recorded in a densely populated (x,y,z) array for a 3D/areal quantitative comparative analysis. Due to this step change, the colloquialism in referring to the crater produced at the centre of the primer during firing as a "firing pin impression" has become a misnomer, leading some to believe that this toolmark is produced via a single process, where the critical variable is the condition of the firing pin.

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Article Synopsis
  • The study aimed to evaluate how different printing orientations affect the fit and gaps of a 3-unit interim fixed partial denture created using two additive manufacturing methods compared to traditional milling.
  • A digital design was printed using stereolithography (SLA) and digital light processing (DLP) technologies, with measurements taken for gaps in various orientations, while milling served as a control.
  • Results indicated that SLA produced comparable fit to milling across all orientations, whereas DLP showed significantly larger gaps, suggesting SLA is more reliable for dental applications.
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Statement Of Problem: Strength-gradient zirconia combining 3 zirconia formulations with different flexural strengths has been reported to have outstanding mechanical properties. However, data concerning the effect of different sintering protocols on the fracture strength of 3-unit monolithic gradient zirconia fixed partial dentures (FPDs) are sparse.

Purpose: The purpose of this in vitro study was to test the effect of different sintering protocols on the fracture strength of 3-unit monolithic gradient zirconia FPDs.

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Statement Of Problem: Polyetheretherketone (PEEK) has been increasingly used as a framework material in prosthetic dentistry. However, data on the marginal and internal fit of PEEK restorations fabricated by using either the computer-aided design and computer-aided manufacturing (CAD-CAM) or heat-pressing technique are sparse.

Purpose: The aim of this in vitro study was to assess the marginal and internal fit of milled and pressed PEEK single crowns by using microcomputed tomography (μCT).

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Biocompatible AlO-hBN ceramic was sintered from AlN and BO precursors by reaction hot pressing at 1750 °C and 30 MPa for 8 min. The ceramic was compared to nonreactive (NR) one sintered from AlO and BN under the same sintering conditions. The NR ceramic possesses 9% porosity as opposed to only 2% porosity for the reaction sintered AlO-hBN.

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We show that heart rate enabled wearable devices can be used to measure respiratory rate. Respiration modulates the heart rate creating excess power in the heart rate variability at a frequency equal to the respiratory rate, a phenomenon known as respiratory sinus arrhythmia. We isolate this component from the power spectral density of the heart beat interval time series, and show that the respiratory rate thus estimated is in good agreement with a validation dataset acquired from sleep studies (root mean squared error = 0.

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The present work aimed at designing and developing a novel 3D printed diffusion cell capable of UV imaging using the fused filament fabrication (FFF) method. UV imaging has proven to be very versatile in the area of pharmaceutics giving insights into various phenomena including the dissolution behaviour of dosage forms, intrinsic dissolution rates and the drug precipitation processes. A 3D printed diffusion cell in the similitude of a Franz cell was successfully printed using polylactic acid (PLA) filaments equipped with quartz for the imaging area.

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Screening manufactured products that are conducted faster to enhance the contemporary manufacture processes and quality is possible by implementing enhanced quality control. Such quality control of manufactured products has increased the market for process-focused precision metrology that can execute evaluations faster while providing significant feedback for the manufacturing system. This investigation examines spatial dispersive interferometry's potential for producing accurate surface profile measurements by emphasizing vertical range measurements and identifying a system that can enable them to increase incrementally while maintaining the results' quality.

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In the absence of biomarkers of protective immunity, newly developed vaccines against bovine tuberculosis need to be evaluated in virulent Mycobacterium bovis challenge experiments, which require the use of expensive and highly in demand Biological Safety Level 3 (BSL3) animal facilities. The recently developed bovine BCG challenge model offers a cheaper and faster way to test new vaccine candidates and additionally reduces the severity of the challenge compared to virulent M. bovis challenge in line with the remits of the NC3Rs.

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Background: Health issues relating to the lower urinary tract are an increasing burden on the health economy. Measurement of urination frequency/volume using diaries to evaluate symptoms and assess severity is established in the management of these health problems. In current practice, these frequency volume diaries are completed by voiding into a measuring jug and the completion of paper or digital charts.

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This study presents a modelling framework to predict the flowability of various commonly used pharmaceutical powders and their blends. The flowability models were trained and validated on 86 samples including single components and binary mixtures. Two modelling paradigms based on artificial intelligence (AI) namely, a radial basis function (RBF) and an integrated network were employed to model the flowability represented by the flow function coefficient (FFC) and the bulk density (RHOB).

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There has recently been an increase in the research and implementation of advanced measurement techniques to ballistic toolmark identification. This has led to a shift from greyscale imaging to the acquisition of dense areal datasets. With the addition of mathematical correlation algorithms, these advanced techniques will be advantageous in criminal investigation.

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The aim of this study was to evaluate the choice of polymer and polymer level on the performance of the microstructure and wettability of hot-melt extruded solid dispersion of Glyburide (Gly) as a model drug. The produced solid dispersion were characterised using scanning electron microscopy (SEM), image analysis using a focus variation instrument (FVI), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), X-ray microtomography (XµT), dynamic contact angle measurement and dissolution analysis using biorelevant dissolution media (FASSIF). SEM and focus variation analysis showed that the microstructure and surface morphology was significantly different between samples produced.

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In order to enhance the measurement availability for manufacturing applications, on-machine surface measurement (OMSM) is integrated onto the machine tools, which avoids the errors caused by re-positioning workpieces and utilizes the machine axes to extend the measuring range as well. However, due to the fact that measurement probe actuation is performed using the machine tool axes, the inherent kinematics error will inevitably induce additional deviations onto the OMSM results. This paper presents a systematic methodology of kinematics error modelling, measurement, and compensation for OMSM on an ultra-precision turning lathe.

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There have been a number of reports on the occurrence of taper corrosion and/or fretting and some have speculated on a link to the occurrence of adverse local tissue reaction specifically in relation to total hip replacement which have a metal-on-metal bearing. As such a study was carried out to compare the magnitude of material loss at the taper in a series of retrieved femoral heads used in metal-on-polyethylene bearings with that in a series of retrieved heads used in metal-on-metal bearings. A total of 36 metal-on-polyethylene and 21 metal-on-metal femoral components were included in the study all of which were received from a customer complaint database.

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Bovine tuberculosis (bTB) remains a globally significant veterinary health problem. Defining correlates of protection can accelerate the development of novel vaccines against TB. As the cultured IFNγ ELISPOT (cELISPOT) assay has been shown to predict protection and duration of immunity in vaccinated cattle, we sought to characterize the phenotype of the responding T-cells.

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It has been speculated that material loss, either as corrosion or wear, at the head-stem taper junction is implicated in the high revision rates reported for metal-on-metal total hip replacements. We measured the volume of material loss from the taper and bearing surfaces of retrieved devices, and investigated the associations with blood metal ion levels and the diagnosis of a cystic or solid pseudotumor. The median volumes of material lost from the female and male taper surfaces were 2.

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Background: It has been reported that bone cement correlates with survivorship of cemented total hip replacement. However, little research has been published to investigate the influence of bone cement type on production of fretting wear on the femoral stem.

Methods: In the present study, we performed six in vitro wear simulations using the same type of femoral stem (polished Exeter V40™) and three different bone cements (Simplex P, Palacos R, and CMW 3).

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Cemented total hip replacement has been performed worldwide to treat patients with osteoarthritis and osteonecrosis, with aseptic loosening as its primary reason for revision. It has been indicated that the stem-cement interfacial porosity may contribute to the early loosening of cemented hip prosthesis. In addition, it is generally accepted that the micropores in bone cement surface and in the bulk material are detrimental to the mechanical integrity of bone cement and act as stress concentrators, resulting in generation of fatigue cracks in the cement mantle.

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Central regulation of cardiac output via the sympathetic and parasympathetic branches of the autonomic nervous system allows the organism to respond to environmental changes. Sudden onset stimuli, startle stimuli, are useful probes to study central regulatory responses to the environment. In mammals, startle stimuli induce a transient bradycardia that habituates with repeated stimulation.

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Cemented total hip replacement has become a standard surgical technique to treat patients with osteoarthritis and osteonecrosis. The stem-cement interface experiences fretting wear in vivo due to low-amplitude oscillatory micromotion under physiological loading, and this wear is currently becoming important as a potential mechanism for the overall wear of cemented total hip replacements. However, the relative micromotion at the stem-cement interface has not been widely reported.

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The great success of cemented total hip replacement to treat patients with endstage osteoarthritis and osteonecrosis has been well documented. However, its long-term survivorship has been compromised by progressive development of aseptic loosening, and few hip prostheses could survive beyond 25 years. Aseptic loosening is mainly attributed to bone resorption which is activated by an in-vivo macrophage response to particulate debris generated by wear of the hip prosthesis.

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Total joint replacement is one of the most common elective surgical procedures performed worldwide, with an estimate of 1.5x 10(6) operations performed annually. Currently joint replacements are expected to function for 10-15 years; however, with an increase in life expectancy, and a greater call for knee replacement due to increased activity levels, there is a requirement to improve their function to offer longer-term improved quality of life for patients.

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