Determination of propofol by GC/MS and fast GC/MS-TOF in two cases of poisoning

Two cases of suspected acute and lethal intoxication caused by propofol were delivered by the judicial authority to the Department of Sciences for Health Promotion and Mother-Child Care in Palermo, Sicily. In the first case a female nurse was found in a hotel room, where she lived with her mother; four 10 mg/mL vials and two 20 mg/mL vials of propofol were found near the decedent along with syringes and needles. In the second case a male nurse was found in the operating room of a hospital, along with a used syringe. In both cases a preliminary systematic and toxicological analysis indicated the presence of propofol in the blood and urine. As a result, a method for the quantitative determination of propofol in biological fluids was optimized and validated using a liquid-liquid extraction protocol followed by GC/MS and fast GC/MS-TOF. In the first case, the concentration of propofol in blood was determined to be 8.1 \u3bcg/mL while the concentration of propofol in the second case was calculated at 1.2 \u3bcg/mL. Additionally, the tissue distribution of propofol was determined for both cases. Brain and liver concentrations of propofol were, respectively, 31.1 and 52.2 \u3bcg/g in Case 1 and 4.7 and 49.1 \u3bcg/g in Case 2. Data emerging from the autopsy findings, histopathological exams as well as the toxicological results aided in establishing that the deaths were due to poisoning, however, the manner of death in each were different: homicide in Case 1 and suicide in Case 2

Bioreactor mechanically guided 3D mesenchymal stem cell chondrogenesis using a biocompatible novel thermo-reversible methylcellulose-based hydrogel

Autologous chondrocyte implantation for cartilage repair represents a challenge because strongly limited by chondrocytes' poor expansion capacity in vitro. Mesenchymal stem cells (MSCs) can differentiate into chondrocytes, while mechanical loading has been proposed as alternative strategy to induce chondrogenesis excluding the use of exogenous factors. Moreover, MSC supporting material selection is fundamental to allow for an active interaction with cells. Here, we tested a novel thermo-reversible hydrogel composed of 8% w/v methylcellulose (MC) in a 0.05 M Na 2 SO 4 solution. MC hydrogel was obtained by dispersion technique and its thermo-reversibility, mechanical properties, degradation and swelling were investigated, demonstrating a solution-gelation transition between 34 and 37 °C and a low bulk degradation (<20%) after 1 month. The lack of any hydrogel-derived immunoreaction was demonstrated in vivo by mice subcutaneous implantation. To induce in vitro chondrogenesis, MSCs were seeded into MC solution retained within a porous polyurethane (PU) matrix. PU-MC composites were subjected to a combination of compression and shear forces for 21 days in a custom made bioreactor. Mechanical stimulation led to a significant increase in chondrogenic gene expression, while histological analysis detected sulphated glycosaminoglycans and collagen II only in loaded specimens, confirming MC hydrogel suitability to support load induced MSCs chondrogenesis

Bioreactor mechanically guided 3D mesenchymal stem cell chondrogenesis using a biocompatible novel thermo-reversible methylcellulose-based hydrogel

Autologous chondrocyte implantation for cartilage repair represents a challenge because strongly limited by chondrocytes' poor expansion capacity in vitro. Mesenchymal stem cells (MSCs) can differentiate into chondrocytes, while mechanical loading has been proposed as alternative strategy to induce chondrogenesis excluding the use of exogenous factors. Moreover, MSC supporting material selection is fundamental to allow for an active interaction with cells. Here, we tested a novel thermo-reversible hydrogel composed of 8% w/v methylcellulose (MC) in a 0.05 M Na 2 SO 4 solution. MC hydrogel was obtained by dispersion technique and its thermo-reversibility, mechanical properties, degradation and swelling were investigated, demonstrating a solution-gelation transition between 34 and 37 °C and a low bulk degradation (<20%) after 1 month. The lack of any hydrogel-derived immunoreaction was demonstrated in vivo by mice subcutaneous implantation. To induce in vitro chondrogenesis, MSCs were seeded into MC solution retained within a porous polyurethane (PU) matrix. PU-MC composites were subjected to a combination of compression and shear forces for 21 days in a custom made bioreactor. Mechanical stimulation led to a significant increase in chondrogenic gene expression, while histological analysis detected sulphated glycosaminoglycans and collagen II only in loaded specimens, confirming MC hydrogel suitability to support load induced MSCs chondrogenesis

From a micro-polymeric pipe to a mini-polymeric pulsating heat pipe

Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.In this work, a preliminary study related to the design and manufacturing of a micro polymeric pipe for micro heat exchangers was performed. Among possible polymeric materials, a thermoplastic copolyester elastomer composed of polybuthylene-terephthalate, as crystalline phase, and long glycol chains, as the amorphous one (Hytrel® 6356, Dupont) was selected, both unloaded and loaded with 7 % w/w carbon powder. A microextrusion process was set up to obtain microtubes and the thermo-mechanical characteristics of the produced pipes were studied. Thermal properties of extruded Hytrel® remained almost the same, in terms of melting temperature (Tm ≅ 208 °C) and enthalpy change of fusion (ΔH ≅ 45 mJ/mg), although the material was C-loaded. The thermomechanical tests performed on unloaded and C-loaded Hytrel® microtubes at 25 and 70 °C (possible working temperature) detected a considerable increase in the mechanical properties of C-loaded Hytrel®, compared to the unloaded one. In particular, a relevant improvement of the elastic modulus at 70 °C for the C-loaded microtubes was observed, demonstrating a better thermal stability at high temperature. Moreover, the fabrication of a micro heat exchanger prototype and prteliminary tests with different cooling fluids confirmed the possibility of using Hytrel® for electronic applications, as a good thermal exchange was evidenced.vk201

Reconstructing nonparametric productivity networks

Network models provide a general representation of inter-connected system dynamics. This ability to connect systems has led to a proliferation of network models for economic productivity analysis, primarily estimated non-parametrically using Data Envelopment Analysis (DEA). While network DEA models can be used to measure system performance, they lack a statistical framework for inference, due in part to the complex structure of network processes. We fill this gap by developing a general framework to infer the network structure in a Bayesian sense, in order to better understand the underlying relationships driving system performance. Our approach draws on recent advances in information science, machine learning and statistical inference from the physics of complex systems to estimate unobserved network linkages. To illustrate, we apply our framework to analyze the production of knowledge, via own and cross-disciplinary research, for a world-country panel of bibliometric data. We find significant interactions between related disciplinary research output, both in terms of quantity and quality. In the context of research productivity, our results on cross-disciplinary linkages could be used to better target research funding across disciplines and institutions. More generally, our framework for inferring the underlying network production technology could be applied to both public and private settings which entail spillovers, including intra-and inter-firm managerial decisions and public agency coordination. This framework also provides a systematic approach to model selection when the underlying network structure is unknown

Self-organizing & stochastic behaviors during the regeneration of hair stem cells

Stem cells cycle through active and quiescent states. Large populations of stem cells in an organ may cycle randomly or in a coordinated manner. Although stem cell cycling within single hair follicles has been studied, less is known about regenerative behavior in a hair follicle population. By combining predictive mathematical modeling with in vivo studies in mice and rabbits, we show that a follicle progresses through cycling stages by continuous integration of inputs from intrinsic follicular and extrinsic environmental signals based on universal patterning principles. Signaling from the WNT/bone morphogenetic protein activator/inhibitor pair is coopted to mediate interactions among follicles in the population. This regenerative strategy is robust and versatile because relative activator/inhibitor strengths can be modulated easily, adapting the organism to different physiological and evolutionary needs

Productivity change in Nigerian seaports after reform: a Malmquist productivity index decomposition approach

During the 1990s, Nigerian seaports were considered inefficient, unsafe due to massive cargo theft (wharf rat phenomenon) and one of the most expensive port systems in the world. This resulted in long turnaround times for ships and increased container dwell times. As a result, port operations were transferred to the private sector through concession contracts. This paper employs a Malmquist productivity index (MPI) technique to benchmark pre-and post-reform total factor productivity growth of the six major Nigeria seaports (Apapa, Calabar, Onne, Port Harcourt, TinCan Island and Warri) for the period 2000–2011 which represents six years before (2000–2005) and six years after (2006–2011) the reform. The results indicate progress in technical efficiency of the ports after reform but deterioration in technological progress. Overall productivity growth was higher in the pre-concession period compared to the post-concession period. The source of pre-concession period productivity growth was technological progress while the change in productivity of the post-concession period is generated by an increase in scale efficiency. This suggests that concessionaires have not brought in the much anticipated investment in modern technology to drive port efficiency. The ports of Calabar and Apapa experienced the highest productivity growth while lowest result was Onne

MXene-Integrated Silk Fibroin-Based Self-Assembly-Driven 3D-Printed Theragenerative Scaffolds for Remotely Photothermal Anti-Osteosarcoma Ablation and Bone Regeneration

Aiming to address the bone regeneration and cancer therapy functionalities in one single material, in this study, we developed a dual-functional theragenerative three-dimensional (3D) aerogel-based composite scaffold from hybridization of photo-cross-linked silk fibroin (SF) biopolymer with MXene (Ti3C2) two-dimensional (2D) nanosheets. To fabricate the scaffold, we first develop a dual-cross-linked SF-based aerogel scaffold through 3D printing and photo-cross-linking of the self-assembly-driven methacrylate-modified SF (SF-MA) gel with controlled pore size, macroscopic geometry, and mechanical stability. In the next step, to endow a remotely controlled photothermal antiosteosarcoma ablation function to fabricated aerogel scaffold, MXene 2D nanosheets with strong near-infrared (NIR) photon absorption properties were integrated into the 3D-printed scaffolds. While 3D-printed MXene-modified dual-cross-linked SF composite scaffolds can mediate the in vitro growth and proliferation of preosteoblastic cell lines, they also endow a strong photothermal effect upon remote irradiation with NIR laser but also significantly stimulate bone mineral deposition on the scaffold surface. Additionally, besides the local release of the anticancer model drug, the generated heat (45-53 ?) mediated the photothermal ablation of cancer cells. The developed aerogel-based composites and chosen therapeutic techniques are thought to render a significant breakthrough in biomaterials' future clinical applications

Research Data Management 'Green Shoots' Pilot Programme, Final Reports

This document contains the final reports of six Research Data Management Green Shoots projects run at Imperial College in 2014