840 research outputs found

    Monitoring Cross-Linking, the Evolution of Refractive Index and the Glass Transition Temperature of an Epoxy Resin Using an Optical Fiber Sensor

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    Hyphenated analytical techniques enable the simultaneous measurement of relevant processing and materials parameters under identical environmental conditions. In the current study, a power-compensated differential scanning calorimeter (DSC) was custom-modified to enable the integration of an optical fibre sensor to monitor in situ the progression of the cross-linking reactions by inferring the evolution of the refractive index. A cleaved optical fibre was used and it served as a Fresnel reflection sensor (FRS). The DSC was calibrated with and without the integrated FRS and it was demonstrated that it did not influence the performance of the DSC. The FRS was calibrated using reference refractive index oils within the DSC. An epoxy/amine resin system was cross-linked at 70 ^oC and the enthalpy of cross-linking and the evolution of the refractive index were monitored simultaneously using the DSC and FRS respectively. After the cross-linking was completed, the DSC was programmed to perform a ramped heating schedule from ambient temperature to 150 ^oC. The FRS was capable of detecting glass transition temperature (Tg) of the cross-linked resin. An excellent correlation was observed for the Tg obtained by the FRS and DSC. The contribution of factors affecting the resolution of the data from the FRS are discussed.</p

    Literature and Environment, the Long View: Thoughts from the Founders of ASLE

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    The Association for the Study of Literature and Environment (ASLE) is the primary professional organization of scholars, teachers, and writers who study the relationships among literature, culture, and the physical environment. At a recent roundtable discussion at the Western American Literature Association's Annual Conference, "flash papers" from ASLE's founders offered a fascinating array of view points reflecting on ASLE's twenty year history. Papers look at wilderness, post naturalism, science fiction, pedagogy, publishing and climate change. It is our hope that the set of papers collected here will commemorate a historical moment and spark a continuing conversation on the future of the organization

    Preventing facial pressure injuries among health care staff working in diverse COVID‐19 care environments

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    The aim of this study was to determine the impact of a specially designed care bundle on the development of facial pressure injuries among frontline health care workers wearing personal protective equipment (PPE) during the COVID-19 pandemic. This was a mixed methods study. First, a pre-posttest observational design was employed to evaluate the impact of the pre-piloted intervention, a care bundle including skin cleansing and hydration, protective material use, facemask selection and skin inspection, developed in line with international best practice guidelines. Data were collected using survey methodology. Frontline COVID-19 staff working in acute, community and ambulance services were invited to participate. Then, judgemental and volunteer sampling was used to select participants to undertake semi-structured interviews to elicit feedback on their perceptions of the care bundle. The sample included 120 acute hospital staff, 60 Ambulance staff, 24 Community Hub staff and 20 COVID-19 testing centre staff. A survey response rate of 61% was realised (n = 135/224). Of the participants, 32% (n = 43) had a facial pressure ulcer (FPI) pre-intervention and 13% (n = 18) developed an FPI while using the care bundle. The odds ratio (OR) was 0.33 (95% CI: 0.18 to 0.61; P = .0004), indicating a 77% reduction in the odds of FPI development with use of the care bundle. Analysis of the qualitative data from 22 interviews identified three key themes, the context for the care bundle, the ease of use of the care bundle and the care bundle as a solution to FPI development. The care bundle reduced the incidence of FPI among the participants and was found to be easy to use. Implementation of skin protection for frontline staff continues to be important given the persistently high incidence of COVID-19 and the ongoing need to wear PPE for protracted durations

    Human Labor Pain Is Influenced by the Voltage-Gated Potassium Channel KV6.4 Subunit.

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    By studying healthy women who do not request analgesia during their first delivery, we investigate genetic effects on labor pain. Such women have normal sensory and psychometric test results, except for significantly higher cuff pressure pain. We find an excess of heterozygotes carrying the rare allele of SNP rs140124801 in KCNG4. The rare variant KV6.4-Met419 has a dominant-negative effect and cannot modulate the voltage dependence of KV2.1 inactivation because it fails to traffic to the plasma membrane. In vivo, Kcng4 (KV6.4) expression occurs in 40% of retrograde-labeled mouse uterine sensory neurons, all of which express KV2.1, and over 90% express the nociceptor genes Trpv1 and Scn10a. In neurons overexpressing KV6.4-Met419, the voltage dependence of inactivation for KV2.1 is more depolarized compared with neurons overexpressing KV6.4. Finally, KV6.4-Met419-overexpressing neurons have a higher action potential threshold. We conclude that KV6.4 can influence human labor pain by modulating the excitability of uterine nociceptors.MCL, DKM, DW, and CGW acknowledge funding from Addenbrooke’s Charitable Trust and the NIHR Cambridge Biomedical Research Centre. MN was funded by the Wellcome Trust (200183/Z/15/Z); JH and ESS by a Rosetrees Postdoctoral Grant (A1296) and the BBSRC (BB/R006210/1); GC and ESS by Versus Arthritis Grants (RG21973); VBL and FR by the Wellcome Trust (106262/Z/14/Z and 106263/Z/14/Z) and a joint MRC programme within the Metabolic Diseases Unit (MRC_MC_UU_12012/3). EF, GI and CB were funded by the Cambridge NIHR Biomedical Research Centre Integrative Genomics theme and LAP by a BBSRC-funded studentship (BB/M011194/1)

    Mouse model for the lysosomal disorder galactosialidosis and correction of the phenotype with overexpressing erythroid precursor cells.

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    The lysosomal storage disorder galactosialidosis results from a primary deficiency of the protective protein/cathepsin A (PPCA), which in turn affects the activities of beta-galactosidase and neuraminidase. Mice homozygous for a null mutation at the PPCA locus present with signs of the disease shortly after birth and develop a phenotype closely resembling human patients with galactosialidosis. Most of their tissues show characteristic vacuolation of specific cells, attributable to lysosomal storage. Excessive excretion of sialyloligosaccharides in urine is diagnostic of the disease. Affected mice progressively deteriorate as a consequence of severe organ dysfunction, especially of the kidney. The deficient phenotype can be corrected by transplanting null mutants with bone marrow from a transgenic line overexpressing human PPCA in erythroid precursor cells. The transgenic bone marrow gives a more efficient and complete correction of the visceral organs than normal bone marrow. Our data demonstrate the usefulness of this animal model, very similar to the human disease, for experimenting therapeutic strategies aimed to deliver the functional protein or gene to affected organs. Furthermore, they suggest the feasibility of gene therapy for galactosialidosis and other disorders, using bone marrow cells engineered to overexpress and secrete the correcting lysosomal protein

    Old World megadroughts and pluvials during the Common Era

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    Climate model projections suggest widespread drying in the Mediterranean Basin and wetting in Fennoscandia in the coming decades largely as a consequence of greenhouse gas forcing of climate. To place these and other “Old World” climate projections into historical perspective based on more complete estimates of natural hydroclimatic variability, we have developed the “Old World Drought Atlas” (OWDA), a set of year-to-year maps of tree-ring reconstructed summer wetness and dryness over Europe and the Mediterranean Basin during the Common Era. The OWDA matches historical accounts of severe drought and wetness with a spatial completeness not previously available. In addition, megadroughts reconstructed over north-central Europe in the 11th and mid-15th centuries reinforce other evidence from North America and Asia that droughts were more severe, extensive, and prolonged over Northern Hemisphere land areas before the 20th century, with an inadequate understanding of their causes. The OWDA provides new data to determine the causes of Old World drought and wetness and attribute past climate variability to forced and/or internal variability

    Macromarketing Pedagogy:Empowering Students to Achieve a Sustainable World

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    The United Nation's Sustainable Development Goals (SDGs) are challenging the world to work towards a more sustainable future. Its 17 goals are ambitious, requiring concerted and system-based efforts driven by critical and socially aware thinking. However, marketing education is largely falling short of teaching students to think that way. Given macromarketing's unique perspective on the interactions among markets, marketing, and society, macromarketers are poised to contribute to marketing pedagogy and to commit students to realizing the SDGs. This article first looks back at the previous 40 years of macromarketing pedagogy, before offering contemporary approaches to teaching macromarketing through four illustrative case studies found in an online repository called Pedagogy Place. It then looks forward, setting an aspiring vision for macro-oriented classrooms in the coming years

    COVID-19 vaccination in patients with immune thrombocytopenia

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    Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by low platelet count and increased bleeding risk. COVID-19 vaccination has been described as risk factor for de novo ITP, but the effects of COVID-19 vaccination in patients with ITP are unknown. Our aims were to investigate the effects of COVID-19 vaccination in ITP patients on platelet count, bleeding complications and ITP exacerbation (any of: ≄50% decline in platelet count; or nadir platelet count 20% decrease from baseline; or use of rescue therapy). Platelet counts of ITP patients and healthy controls were collected immediately before, 1 and 4 weeks after first and second vaccination. Linear mixed-effects modelling was applied to analyze platelet counts over time. We included 218 ITP patients (50.9% female, mean age 55 years and median platelet count of 106x109/L) and 200 healthy controls (60.0% female, mean age 58 years and median platelet count of 256x109/L). Platelet counts decreased by 6.3% after vaccination. We observed no difference in decrease between the groups. Thirty ITP patients (13.8%, 95%CI 9.5%-19.1%) had an exacerbation and 5 (2.2%, 95%CI 0.7%-5.3%) suffered from a bleeding event. Risk factors for ITP exacerbation were platelet count <50x109/L (OR 5.3, 95%CI 2.1-13.7), ITP treatment at time of vaccination (OR 3.4, 95%CI 1.5-8.0) and age (OR 0.96 per year, 95%CI 0.94-0.99). Our study highlights safety of COVID-19 vaccination in ITP patients and importance of close monitoring platelet counts in a subgroup of ITP patients. ITP patients with exacerbation responded well on therapy
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