Effect of pressure and temperature on interfacial tension of poly lactic acid melt in supercritical carbon dioxide

© 2015. This manuscript version of Effect of Pressure and Temperature on Interfacial Tension of Poly lactic acid melt in supercritical carbon dioxide is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the accepted manuscript version of a published article. Published by Elsevier in the journal "Thermochimica Acta" volume 609, http://dx.doi.org/10.1016/j.tca.2015.04.005The interfacial tension of poly lactic acid (PLA) melt is measured in supercritical carbon dioxide (CO2) at the temperature range of 143 °C to 168 °C and CO2 pressures up to 2000 psi, using Axisymmetric Drop Shape Analysis Profile (ADSA-P). The results show a decrease in interfacial tension with increasing temperature and pressure. However, the interfacial tension dependency on temperature at high pressures decreases because of a reduction in CO2 solubility at high temperatures. The relationship between the interfacial tension and the density-difference of polymer-supercritical CO2 mixtures is also examined by the generalized Macleod equation. Moreover, the range of stability for the melted drop, in interfacial tension measurements, is obtained by dimensionless Bond number. The results indicate the validity of the measurements for Bond number between 0.36 and 0.48.Natural Sciences and Engineering Research Council (NSERC) Network for Innovative Plastic Materials and Manufacturing Processes (NIPMMP) Canada Research Chairs (CRC

Pneumothorax complicating isolated clavicle fracture

Isolated clavicle fractures are among the commonest of traumatic fractures in the emergency department. Complications of isolated clavicle fractures are rare. Pneumothorax has been described as a complication of a fractured clavicle only rarely in English literature. In all the reported cases, the pneumothorax was treated by a thoracostomy and the clavicle fracture was treated conservatively. In our case, the pneumothorax required a chest drain insertion and the clavicle fracture was treated surgically with good result

Citizen Seismology in the Arctic

Landslides, earthquakes and other natural disasters are expected to increase in the Arctic, yet our ability to make informed decisions about safety is tightly limited by lack of data. As part of the Integrated Arctic Observation System (INTAROS) project, geophones were installed by residents in Greenland and by University of Bergen in Svalbard in 2018. The purpose of the installations was to explore challenges and benefits of community-based data collection for seismological monitoring in the Arctic region. Raspberry Shake units with one/three-component velocity sensors were selected for the deployment, due to their user-friendly configuration, easy installation, and well established digital platform and web services. The purpose of engaging community members in the use of geophone sensors was to monitor earthquakes, cryoseisms (events generated by ice mass), and landslides. We report our findings with respect to challenges regarding the installation and operation of the Raspberry Shake sensors at both locations. Connecting community-based recordings with permanent seismological networks improved both the detection capability and the data support for understanding seismic events in Greenland. In contrast, finding suitable locations for deployments in Longyearbyen turned out to be challenging, because most buildings are constructed on poles due to the permafrost and indoor space is expensive. Promoting citizen seismology in the Arctic could improve monitoring of seismic events in the Arctic while simultaneously raising community awareness of natural hazards.publishedVersio

Adsorption of surface-modified silica nanoparticles to the interface of melt poly (lactic acid) and supercritical carbon dioxide

Natural Sciences and Engineering Research Council (NSERC) Network for Innovative Plastic Materials and Manufacturing Processes (NIPMMP) Canada Research Chairs (CRC)With the purpose of fabricating polymer nanocomposite foams and preventing coalescence in foaming processes, the interfacial tension of poly (lactic acid) (PLA) -silica composites is investigated in this work. Synthesized silica nanoparticles(SNs) with a CO2 - philic surface modification are used as the dispersednanoparticles. Interfacial tension is a key parameter in processing of polymer foamssince it directly affects the final foam properties, such as cell size and cell density.Interfacial tension of silica-containing PLA and supercritical carbon dioxide (CO2)is measured using Axisymmetric Drop Shape Analysis Profile (ADSA-P) pendantdrop method at high pressures and high temperatures. The interfacial tensionbetween PLA and supercritical CO2 is observed to decrease as a result ofnanoparticles’ adsorption to the interface. These results indicate that the reductionin interfacial tension with increasing silica content significantly deviates from alinear trend; there is a minimum at 2 wt. % loading of the SNs and then the interfacialtension curve reaches a plateau. Contact angle measurements show an affinity of theSNs for the polymer-supercritical CO2 interface, and these obtained results are usedto calculate the binding energy of the nanoparticles to the PLA / CO2 interface. Inaddition to interfacial properties, the adsorption of silica nanoparticles at theinterface is also studied in detail with Scanning Electron Microscopy

Genetic diversity and population structure of Leishmania infantum from Southeastern France : evaluation using Multi-Locus Microsatellite Typing

In the south of France, Leishmania infantum is responsible for numerous cases of canine leishmaniasis (CanL), sporadic cases of human visceral leishmaniasis (VL) and rare cases of cutaneous and muco-cutaneous leishmaniasis (CL and MCL, respectively). Several endemic areas have been clearly identified in the south of France including the Pyrenees-Orientales, Cevennes (CE), Provence (P), Alpes-Maritimes (AM) and Corsica (CO). Within these endemic areas, the two cities of Nice (AM) and Marseille (P), which are located 150 km apart, and their surroundings, concentrate the greatest number of French autochthonous leishmaniasis cases. In this study, 270 L. infantum isolates from an extended time period (1978-2011) from four endemic areas, AM, P, CE and CO, were assessed using Multi-Locus Microsatellite Typing (MLMT). MLMT revealed a total of 121 different genotypes with 91 unique genotypes and 30 repeated genotypes. Substantial genetic diversity was found with a strong genetic differentiation between the Leishmania populations from AM and P. However, exchanges were observed between these two endemic areas in which it seems that strains spread from AM to P. The genetic differentiations in these areas suggest strong epidemiological structuring. A model-based analysis using STRUCTURE revealed two main populations: population A (consisting of samples primarily from the P and AM endemic areas with MON-1 and non-MON-1 strains) and population B consisting of only MON-1 strains essentially from the AM endemic area. For four patients, we observed several isolates from different biological samples which provided insight into disease relapse and re-infection. These findings shed light on the transmission dynamics of parasites in humans. However, further data are required to confirm this hypothesis based on a limited sample set. This study represents the most extensive population analysis of L. infantum strains using MLMT conducted in France

Characterization and applications of auto-locked vacuum-sealed diode lasers for precision metrology

We demonstrate the performance characteristics of a new class of vacuum-sealed, autolocking diode laser systems and their applications to precision metrology. The laser is based on adaptations of a design that uses optical feedback from an interference filter and it includes a vacuum-sealed cavity, an interchangeable base-plate, and an autolocking digital controller. A change of the base-plate allows operation at desired wavelengths in the visible and near infrared spectral range, whereas the autolocking ability allows the laser to be tuned and frequency stabilized with respect to atomic, molecular, and solid-state resonances without human intervention using a variety of control algorithms programmed into the same controller. We characterize the frequency stability of this laser system based on the Allan deviation (ADEV) of the beat note and of the lock signal. We find that the ADEV floor of 2 × 10−12 and short-term linewidth of ∼200 kHz are strongly influenced by current noise and vacuum sealing. Reducing the current noise and cavity pressure decreases the ADEV floor and increases the averaging time at which the floor occurs, which is a signature of long-term stability. We also show that evacuating the cavity to ∼1 Torr reduces the range of the correction signal of the feedback loop by approximately one order of magnitude, thereby increasing the lock range of the controller. The long-term stability allows the laser to be incorporated into a commercial gravimeter for accurate measurements of gravitational acceleration at the level of a few parts-per-billion, which are comparable to values obtained with an iodine-stabilized He–Ne laser. The autolocking and pattern-matching features of the controller allow the laser to be tuned and stabilized with respect to a temperature tunable transmission spectrum of a fiber-Bragg grating. This capability may be suitable for the development of a differential absorption LIDAR transmitter that can generate data at both on-line and off-line lock points using a single laser

Effect of a multinutrient intervention after ischemic stroke in female C57Bl/6 mice.

Stroke can affect females very differently from males, and therefore preclinical research on underlying mechanisms and the effects of interventions should not be restricted to male subjects, and treatment strategies for stroke should be tailored to benefit both sexes. Previously, we demonstrated that a multinutrient intervention (Fortasyn) improved impairments after ischemic stroke induction in male C57Bl/6 mice, but the therapeutic potential of this dietary treatment remained to be investigated in females. We now induced a transient middle cerebral artery occlusion (tMCAo) in C57Bl/6 female mice and immediately after surgery switched to either Fortasyn or an isocaloric Control diet. The stroke females performed several behavioral and motor tasks before and after tMCAo and were scanned in an 11.7 Tesla MRI scanner to assess brain perfusion, integrity and functional connectivity. To assess brain plasticity, inflammation and vascular integrity, immunohistochemistry was performed after sacrifice of the mice. We found that the multinutrient intervention had diverse effects on the stroke-induced impairments in females. Similar to previous observations in male stroke mice, brain integrity, sensorimotor integration and neurogenesis benefitted from Fortasyn, but impairments in activity and motor skills were not improved in female stroke mice. Overall, Fortasyn effects in the stroked females seem more modest in comparison to previously investigated stroked male mice. We suggest that with further optimization of treatment protocols more information on the efficacy of specific interventions in stroked females can be gathered. This in turn will help with the development of (gender-specific) treatment regimens for cerebrovascular diseases such as stroke

Optimization of high‐pressure processing in extraction of astaxanthin from Penaeus monodon carapace using response surface methodology

Penaeus monodon is a species of shrimp with astaxanthin content that prevents various diseases and enhances immune system. High‐pressure processing (HPP) is capable of achieving higher extraction astaxanthin yield within short processing time. The aim of this research was to optimize the extraction condition of astaxanthin from P. monodon using HPP using response surface methodology (RSM). The investigation was carried out using variables: pressure (150–250 MPa), holding time (10–20 min), and amount of acetone‐methanol mixture, 7:3, vol/vol (3–7 ml). The optimum condition was achieved at the pressure of 238.54 MPa, 16.29 min of holding time, and 6.59 ml of solvent mixture. The optimum yield of astaxanthin was 95.17 μg/gdw. The R2 value was 0.9836 and the adjusted‐R2 value was 0.9688. These values indicate that the application of RSM to optimize the yield of astaxanthin with HPP has a significant impact in enhancing the yield of astaxanthin

Nestin, a neuroectodermal stem cell marker, is expressed by bovine sertoli cells

Nestin, an intermediate filament protein is expressed by neuroectodermal stem cells and tumors originating from cells of neuroectodermal and mesenchymal lineages. Nestin expression is prominent in embryos and remains upregulated until 3-6 weeks after birth but is downregulated afterward. Sertoli cells are nucleated somatic cells that are spanned in the seminiferous epithelium and play a critical role in supporting and controlling germ-cell development. In this context, we employed immunocytochemical, Western blot, and Flow cytometric analyses to demonstrate nestin expression in bovine sertoli cells. Immunostaining clearly showed that setoli cells express high levels of nestin, a result which was confirmed by Western blot analysis of purified cells. Intracellular staining of sertoli cells by flow cytometry revealed that around 74 of the cells express this marker. Given the high expression of vimentin by sertoli cells, it is proposed that the expression of nestin in these cells might be required for the formation of stable vimentin/nestin intermediate filament network. In light of these findings, it seems that sertoli cells of mature bull have potentiality of proliferation. © 2010 Springer-Verlag London Limited

A Proposal for Expansion of the Medical Specialty of Rehabilitation Medicine

The workforce of the medical specialty of Rehabilitation Medicine (RM) in the UK is 10 times less than the European average for the specialty of Physical and Rehabilitation Medicine (PRM). This can be explained partly by the difference in the scope of practice within the specialty between the UK and other European countries and USA. This opinion paper aims to compare the rehabilitation needs in chronic medical conditions and compare the scope of practice between countries within Europe and other regions of the world. The potential advantages of a broader remit specialty to improve rehabilitation care for patients by involving rehabilitation physicians in various medical conditions is explored. Recommendations have been put forward in the Rehabilitation Medicine Expansion Proposal (RMEP), which is likely to make the medical specialty of RM/ PRM more satisfying for the doctors working in the specialty and a more attractive career choice for those entering training in the specialty. There is a need for an international universal framework for the scope of the specialty to have a greater impact on improving the lives of those with chronic medical conditions