Introduction: Methadone hydrochloride (MDN) is an effective pharmacological substitution treatment for opioids dependence, adopted in different countries as methadone maintenance treatment (MMT) programmes. However, MDN can exacerbate the addiction problem if it is abused and injected intravenously, and the frequent visits to the MMT centres can reduce patient compliance. The overall aim of this study is to develop a novel extended-release capsule of MDN using the sol-gel silica (SGS) technique that has the potential to counteract medication-tampering techniques and associated health risks and reduce the frequent visits to MMT centres. Methods: For MDN recrystallisation, a closed container method (CCM) and hot-stage method (HSM) were conducted, and MDN crystals were characterised using the polarised light microscope (PLM). MDN crystal thickness was determined by scanning electron microscopy (SEM) and confocal microscopy (CM) to establish a relationship between MDN crystals thickness and their birefringence colours using the Michel-Levy Birefringence Colour Chart. The experimental series was continued to produce novel silica-based MDN formulations A and B capsules by adding MDN powder at the end and beginning of the SGS process, respectively. The silica-based MDN formulations were characterised by Fourier transform infrared (FT-IR), SEM, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), PLM and mean grey value (MGV) analyses. The in vitro release studies (n=3) for the silica-based MDN formulations and pure MDN capsules were conducted in a phosphate buffer solution (pH= 7.2) for 7 days. Stability studies were conducted for 1 month by keeping the silica-based MDN capsules under 25°C and 57% RH. Results: The optimal method to produce large numbers of MDN crystals was the CCM, and MDN crystals were characterised as diamond shaped with an intrinsic angle of 62o. The SEM surpassed the CM in measuring MDN crystal thickness, and Mann-Whitney U Test showed statistically significant differences between SEM and confocal thickness measurements (U= 1283, p < 0.05) as the SEM exhibited thinner diamond crystals (6.62 ± 2.9 µm) than the CM measurements (9.6 ± 4.6µm). According to the Michel-Levey birefringence colour chart (using the SEM mean thickness of MDN crystals and their retardation value of 428 nm), most of MDN crystals demonstrated a yellow colour. The FT-IR, SEM, DSC, MGV and PLM analyses of both silica-based MDN formulations revealed that MDN was successfully incorporated inside the silica network producing amorphous material (with no appearance of the melting peak of pure MDN at 233.4°C) with evidence of no physical or chemical interaction between sol-gel silica and MDN. However, the TGA analysis revealed a significantly greater amount of MDN was loaded inside the silica-based MDN formulation B compared to A (t = 2.80, p = 0.009, n=6), as 28.3 ± 0.6 mg of MDN was loaded in the former while 25.6 ± 0.7 mg in the latter. In addition, the silica-based MDN formulation B released 10% more MDN after 7 days than formulation A, and both formulations were stable when stored for 1 month under 57% RH and 25°C. Conclusion: The novel combined use of SEM and PLM techniques shows a potential for the identification of MDN in forensic science as it established a range of birefringence colours of MDN crystals. Moreover, the new silica-based MDN formulation B can help to deter MDN abuse and increase patient adherence to MMT due to its potential to sustain MDN release and reduce the frequent visits to MDN treatment centres.
Epithelial ovarian cancer is the leading cause of cancer deaths from gynecological malignancies. Angiogenesis is considered essential for tumor growth and the development of metastases. VEGF and IL?8 are potent angiostimulatory molecules and their expression has been demonstrated in many solid tumors, including ovarian cancer.VEGF and IL-8 concentrations were measured by ELISA test (HumanVEGF,IL-8). Bioassay ELISA/ US Biological / USA).The median VEGF and IL-8 levels were significantly higher in the sera of ovarian cancer patients than in those with benign tumors and in healthy controls.Pretreatment VEGF and IL-8 serum levels might be regarded as an additional tool in the differentiation of ovarian tumors.
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The implementation of nanotechnology in all industries is one of most significant research fields. Nanoparticles have shown a promising application in subsurface fields. On the other hand, various surfactants have been used in the oil industry to reduce oil/water interfacial tension and also widely used to stabilize the nano-suspensions. The primary objective of this study was to investigate the improvements of surfactants ability in term of interfacial tension (γ) reduction utilizing addition of silicon dioxide nanoparticles at different temperatures and salinity. The pendant drop technique has been used to measure γ and electrical conductivity has been used to measure the critical micelle concentration (CMC). The synergistic effects of
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Changing oil-wet surfaces toward higher water wettability is of key importance in subsurface engineering applications. This includes petroleum recovery from fractured limestone reservoirs, which are typically mixed or oil-wet, resulting in poor productivity as conventional waterflooding techniques are inefficient. A wettability change toward more water-wet would significantly improve oil displacement efficiency, and thus productivity. Another area where such a wettability shift would be highly beneficial is carbon geo-sequestration, where compressed CO2 is pumped underground for storage. It has recently been identified that more water-wet formations can store more CO2. We thus examined how silica based nanofluids can induce such a wettabil
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Objectives: Small field of view gamma detection and imaging technologies for monitoring in vivo tracer uptake are rapidly expanding and being introduced for bed-side imaging and image guided surgical procedures. The Hybrid Gamma Camera (HGC) has been developed to enhance the localization of targeted radiopharmaceuticals during surgical procedures; for example in sentinel lymph node (SLN) biopsies and for bed-side imaging in procedures such as lacrimal drainage imaging and thyroid scanning. In this study, a prototype anthropomorphic head and neck phantom has been designed, constructed, and evaluated using representative modelled medical scenarios to study the capability of the HGC to detect SLNs and image small organs. Methods: An anthropom
... Show MoreA novel demountable shear connector for precast steel‐concrete composite bridges is presented. The connector uses high‐strength steel bolts, which are fastened to the top flange of the steel beam with the aid of a special locking nut configuration that prevents slip of bolts within their holes. Moreover, the connector promotes accelerated construction and overcomes typical construction tolerances issues of precast structures. Most importantly, the connector allows bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (i) precast deck panels can be rapidly uplifted and replaced; (ii) connectors can be rapidly removed and replaced; and (iii) steel beams can b
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