180 research outputs found

    Enhancement in Electro-Optic Properties of Dynamic Scattering Systems through Addition of Dichroic Dyes

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    Electro-optic properties of dynamic scattering in homeotropically aligned pure and dichroic dye-doped nematic liquid crystal samples are examined. The optical properties of the two systems are quantified using transmission properties of scattered and unscattered as a function of amplitude and frequency of an applied voltage. Auto-correlation of the scattered signal at different applied voltages is used to compare the decay times in the two systems. Lastly, the histogram of the scattered signal reveals a wavevector dependent large light scattering event. The dye-doped system shows a significant enhancement of light blocking property in both normal and off-axis light propagation. The characteristics of the system are compared to other scattering technologies. The results suggest that dye-doped system can overcome shortcomings in scattering based devices used for near-eye applications

    Évaluation d'une nouvelle expĂ©rience clinique immersive en rĂ©alitĂ© virtuelle pour amĂ©liorer le programme d'Ă©ducation mĂ©dicale

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    Implication Statement Medical students often find the transition to clerkship challenging and stressful.  The use of virtual reality (VR) technologies such as screen-based learning, 360-video and immersive VR using head-mount-devices is becoming more utilized in medical education. Immersive technologies in particular have been shown to lead to greater enthusiasm and provide higher knowledge gain for students compared to screen-based VR. The University of British Columbia Faculty of Medicine has developed a novel immersive patient experience using VR to enhance the clinical skills program and evaluate student perception regarding its formal integration into curricula. Students reported positive feedback on the experience, and interest in more immersive learning opportunities in future sessions. VR technology has the potential to enhance medical education and provide a safe immersive learning environment to build clinical acumen.ÉnoncĂ© des implications de la recherche Les Ă©tudiants en mĂ©decine trouvent souvent la transition vers l'externat difficile et stressante.  L'utilisation des technologies de rĂ©alitĂ© virtuelle (RV), telles que l'apprentissage sur Ă©cran, la vidĂ©o Ă  360° et la RV immersive Ă  l'aide d'appareils montĂ©s sur la tĂȘte, est de plus en plus rĂ©pandue dans l'Ă©ducation mĂ©dicale. Il a Ă©tĂ© dĂ©montrĂ© que les technologies immersives, en particulier, suscitent un plus grand enthousiasme et permettent aux Ă©tudiants d'acquĂ©rir davantage de connaissances que la RV sur Ă©cran. La facultĂ© de mĂ©decine de l'UniversitĂ© de la Colombie-Britannique a mis au point une nouvelle expĂ©rience immersive du patient en utilisant la RV pour amĂ©liorer le programme de compĂ©tences cliniques et Ă©valuer la perception des Ă©tudiants concernant son intĂ©gration formelle dans les programmes d'Ă©tudes. Les Ă©tudiants ont fait part de leurs rĂ©actions positives Ă  l'Ă©gard de l'expĂ©rience et de leur intĂ©rĂȘt pour des possibilitĂ©s d'apprentissage plus immersives dans les sessions futures. La technologie de la RV a le potentiel d'amĂ©liorer l'Ă©ducation mĂ©dicale et de fournir un environnement d'apprentissage immersif sĂ»r pour dĂ©velopper le sens clinique

    Hemato-immunological, serum metabolite and enzymatic stress response alterations in exposed rainbow trout (Oncorhynchus mykiss) to nanosilver

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    The aim of present study was to investigate the effects of sub-lethal concentrations of silver nanoparticles (AgNP) on hematological parameters, differential tests of white blood cells, serum metabolite parameters, serum enzymes activity and serum ions in rainbow trout, Oncorhynchus mykiss. Healthy rainbow trout, were exposed to sub-lethal concentrations (0, 1.5 and 2.5 ppm) of nanosilver for 14 days. RBC, WBC and Hct levels were significantly (P<0.05) increased in exposed groups. Within the white blood cells, only neutrophils showed a significant increase at 7 and 14 days post exposure (P<0.05). Serum triglyceride, total serum protein, albumin and globulin levels were decreased (P<0.05) in exposed fish, however, cholesterol levels increased in the 2.5 ppm group at 7 days after exposure (P<0.05). Cortisol and glucose increased significantly at 7 and 14 days of exposure in both concentrations of AgNPs (P<0.05). Decreases in serum ions level were observed, although reduction in chloride ions occurred earlier and more severe than other measured parameters (P<0.05). Elevation in serum ALP, LDH, ALT and AST enzymes were observed during the experiment (P<0.05), although SOD and CAT activity were significantly decreased in exposed groups (P<0.05). The results revealed that AgNP can affect the hematological, serum metabolite and enzymatic parameters of O. mykiss, as well as AgNP exposure induce a general oxidative stress response in O. mykiss

    Future Perspectives in Spinal Cord Repair: Brain as Saviour? TSCI with Concurrent TBI: Pathophysiological Interaction and Impact on MSC Treatment

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    Traumatic spinal cord injury (TSCI), commonly caused by high energy trauma in young active patients, is frequently accompanied by traumatic brain injury (TBI). Although combined trauma results in inferior clinical outcomes and a higher mortality rate, the understanding of the pathophysiological interaction of co-occurring TSCI and TBI remains limited. This review provides a detailed overview of the local and systemic alterations due to TSCI and TBI, which severely affect the autonomic and sensory nervous system, immune response, the blood-brain and spinal cord barrier, local perfusion, endocrine homeostasis, posttraumatic metabolism, and circadian rhythm. Because currently developed mesenchymal stem cell (MSC)-based therapeutic strategies for TSCI provide only mild benefit, this review raises awareness of the impact of TSCI-TBI interaction on TSCI pathophysiology and MSC treatment. Therefore, we propose that unravelling the underlying pathophysiology of TSCI with concomitant TBI will reveal promising pharmacological targets and therapeutic strategies for regenerative therapies, further improving MSC therapy

    The Efficacy and Safety of Apremilast, Etanercept and Placebo in Patients with Moderate-to-Severe Plaque Psoriasis: 52-week Results from a Phase IIIb, Randomized, Placebo-Controlled Trial (LIBERATE).

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    BACKGROUND: Apremilast, an oral, small-molecule phosphodiesterase 4 inhibitor, has demonstrated efficacy in patients with moderate-to-severe psoriasis. OBJECTIVE: Evaluate efficacy and safety of apremilast vs. placebo in biologic-naive patients with moderate-to-severe plaque psoriasis and safety of switching from etanercept to apremilast in a phase IIIb, randomized, double-blind, placebo-controlled study (NCT01690299). METHODS: Two hundred and fifty patients were randomized to placebo (n = 84), apremilast 30 mg BID (n = 83) or etanercept 50 mg QW (n = 83) through Week 16; thereafter, all patients continued or switched to apremilast through Week 104. The primary efficacy endpoint was achievement of PASI-75 at Week 16 with apremilast vs. placebo. Secondary endpoints included achievement of PASI-75 at Week 16 with etanercept vs. placebo and improvements in other clinical endpoints vs. placebo at Week 16. Outcomes were assessed through Week 52. This study was not designed for apremilast vs. etanercept comparisons. RESULTS: At Week 16, PASI-75 achievement was greater with apremilast (39.8%) vs. placebo (11.9%; P \u3c 0.0001); 48.2% of patients achieved PASI-75 with etanercept (P \u3c 0.0001 vs. placebo). PASI-75 response was maintained in 47.3% (apremilast/apremilast), 49.4% (etanercept/apremilast) and 47.9% (placebo/apremilast) of patients at Week 52. Most common adverse events (≄5%) with apremilast, including nausea, diarrhoea, upper respiratory tract infection, nasopharyngitis, tension headache and headache, were mild or moderate in severity; diarrhoea and nausea generally resolved in the first month. No new safety or tolerability issues were observed through Week 52 with apremilast. CONCLUSION: Apremilast demonstrated significant efficacy vs. placebo at Week 16 in biologic-naive patients with psoriasis, which was sustained over 52 weeks, and demonstrated safety consistent with the known safety profile of apremilast. Switching from etanercept to apremilast did not result in any new or clinically significant safety findings, and efficacy was maintained with apremilast through Week 52

    Trade-offs in multi-purpose land use under land degradation

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    CITATION: Vlek, P. L. G., et al. 2017. Trade-offs in multi-purpose land use under land degradation. Sustainability, 9(12):2196, doi:10.3390/su9122196.The original publication is available at http://www.mdpi.com/journal/sustainabilityAbstract: Land provides a host of ecosystem services, of which the provisioning services are often considered paramount. As the demand for agricultural products multiplies, other ecosystem services are being degraded or lost entirely. Finding a sustainable trade-off between food production and one or more of other ecosystem services, given the variety of stakeholders, is a matter of optimizing land use in a dynamic and complex socio-ecological system. Land degradation reduces our options to meet both food demands and environmental needs. In order to illustrate this trade-off dilemma, four representative services, carbon sinks, water storage, biodiversity, and space for urbanization, are discussed here based on a review of contemporary literature that cuts across the domain of ecosystem services that are provided by land. Agricultural research will have to expand its focus from the field to the landscape level and in the process examine the cost of production that internalizes environmental costs. In some situations, the public cost of agriculture in marginal environments outweighs the private gains, even with the best technologies in place. Land use and city planners will increasingly have to address the cost of occupying productive agricultural land or the conversion of natural habitats. Landscape designs and urban planning should aim for the preservation of agricultural land and the integrated management of land resources by closing water and nutrient cycles, and by restoring biodiversity.https://www.mdpi.com/2071-1050/9/12/2196Publisher's versio

    Maladaptive behaviors are linked with inefficient sleep in individuals with developmental disabilities

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    The purpose of the current study was to assess the relations between nightly sleep patterns and the frequency of daily maladaptive behavior. Antecedent and consequential relations between sleep patterns and behavior were evaluated with time series analysis. Sleep efficiency and maladaptive behavior were determined for 20 female residents of an institutional care facility for adults with developmental disabilities. Daily maladaptive behavioral data and nightly sleep/awake logs were collected for 4 months for each participant. Efficient sleep patterns were significantly associated with lower frequencies of maladaptive behaviors. All lagged cross-correlations 8 days before and 8 days after an evening of sleep were significant. These findings suggested that inefficient sleep was associated with increased maladaptive behaviors and that the lagged associations reflected a chronic but not an acute linkage between sleep and behavior

    Combining Nitrous Oxide with Carbon Dioxide Decreases the Time to Loss of Consciousness during Euthanasia in Mice — Refinement of Animal Welfare?

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    Carbon dioxide (CO2) is the most commonly used euthanasia agent for rodents despite potentially causing pain and distress. Nitrous oxide is used in man to speed induction of anaesthesia with volatile anaesthetics, via a mechanism referred to as the “second gas” effect. We therefore evaluated the addition of Nitrous Oxide (N2O) to a rising CO2 concentration could be used as a welfare refinement of the euthanasia process in mice, by shortening the duration of conscious exposure to CO2. Firstly, to assess the effect of N2O on the induction of anaesthesia in mice, 12 female C57Bl/6 mice were anaesthetized in a crossover protocol with the following combinations: Isoflurane (5%)+O2 (95%); Isoflurane (5%)+N2O (75%)+O2 (25%) and N2O (75%)+O2 (25%) with a total flow rate of 3l/min (into a 7l induction chamber). The addition of N2O to isoflurane reduced the time to loss of the righting reflex by 17.6%. Secondly, 18 C57Bl/6 and 18 CD1 mice were individually euthanized by gradually filling the induction chamber with either: CO2 (20% of the chamber volume.min−1); CO2+N2O (20 and 60% of the chamber volume.min−1 respectively); or CO2+Nitrogen (N2) (20 and 60% of the chamber volume.min−1). Arterial partial pressure (Pa) of O2 and CO2 were measured as well as blood pH and lactate. When compared to the gradually rising CO2 euthanasia, addition of a high concentration of N2O to CO2 lowered the time to loss of righting reflex by 10.3% (P<0.001), lead to a lower PaO2 (12.55±3.67 mmHg, P<0.001), a higher lactataemia (4.64±1.04 mmol.l−1, P = 0.026), without any behaviour indicative of distress. Nitrous oxide reduces the time of conscious exposure to gradually rising CO2 during euthanasia and hence may reduce the duration of any stress or distress to which mice are exposed during euthanasia

    Blood-brain barrier failure as a core mechanism in cerebral small vessel disease and dementia: evidence from a cohort study

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    Introduction: Small vessel disease (SVD) is a common contributor to dementia. Subtle blood-brain barrier (BBB) leakage may be important in SVD-induced brain damage. Methods: We assessed imaging, clinical variables, and cognition in patients with mild (i.e., nondisabling) ischemic lacunar or cortical stroke. We analyzed BBB leakage, interstitial fluid, and white matter integrity using multimodal tissue-specific spatial analysis around white matter hyperintensities (WMH). We assessed predictors of 1 year cognition, recurrent stroke, and dependency. Results: In 201 patients, median age 67 (range 34–97), BBB leakage, and interstitial fluid were higher in WMH than normal-appearing white matter; leakage in normal-appearing white matter increased with proximity to WMH (P , .0001), with WMH severity (P 5 .033), age (P 5 .03), and hypertension (P , .0001). BBB leakage in WMH predicted declining cognition at 1 year. Discussion: BBB leakage increases in normal-appearing white matter with WMH and predicts worsening cognition. Interventions to reduce BBB leakage may prevent SVD-associated dementia

    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe
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