86 research outputs found

    On the crystallization behavior of syndiotactic-b-atactic polystyrene stereodiblock copolymers, atactic/syndiotactic polystyrene blends, and aPS/sPS blends modified with sPS-b-aPS

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    International audienceCrystallization and morphological features of syndiotactic-b-atactic polystyrene stereodiblock copolymers (sPS-b-aPS), atactic/syndiotactic polystyrene blends (aPS/sPS), and aPS/sPS blends modified with sPS-b-aPS, with different compositions in aPS and sPS, have been investigated using differential scanning calorimetry (DSC), polarized light optical microscopy (POM) and wide angle X-ray diffraction (WAXRD) techniques. For comparative purposes, the properties of parent pristine sPS samples were also studied. WAXRD analyses revealed for all the samples, independently from their composition (aPS/sPS ratio) and structure (blends, block copolymers, blends modified with block copolymers), the same polymorphic β form of sPS. The molecular weight of aPS and sPS showed opposite effects on the crystallization of 50:50 aPS/sPS blends: the lower the molecular weight of aPS, the slower the crystallization while the lower the molecular weight of sPS, the faster the crystallization. DSC studies performed under both isothermal and non-isothermal conditions, independently confirmed by POM studies, led to a clear trend for the crystallization rate at a given sPS/aPS ratio (ca. 50:50 and 20:80): sPS homopolymers > sPS-b-aPS block copolymers ∼sPS/aPS blends modified with sPS-b-aPS copolymers > sPS/aPS blends. Interestingly, sPS-b-aPS block copolymers not only crystallized faster than blends, but also affected positively the crystallization behavior of blends. At 50:50 sPS/aPS ratio, blends (Blend-2), block copolymers (Cop-1) and blends modified with block copolymers (Blend-2-mod) crystallized via spherulitic crystalline growth controlled by an interfacial process. In all cases, an instantaneous nucleation was observed. The density of nuclei in block copolymers (160,000−190,000 nuclei mm−3) was always higher than that in blends and modified blends (30,000−60,000 nuclei mm−3), even for quite different sPS/aPS ratio. At 20:80 sPS/aPS ratio, the block copolymers (Cop-2) preserved the same crystallization mechanism than at 45:55 ratio (Cop-1). On the other hand, the 20:80 sPS/aPS blend (Blend-4) and blend modified with block copolymers (Blend-4-mod) showed a spinodal decomposition

    Not Your “Typical” Research: Inclusion Ethics in Neurodiversity Scholarship

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    Research focusing on neurodiversityFootnote1 is critical for including all marginalized populations in the organizational diversity literature and for promoting theoretical innovation. It is imperative that such research models the ethics of inclusion (Gowen et al., Reference Gowen, Taylor, Bleazard, Greenstein, Baimbridge and Poole2019; Nicolaidis et al., Reference Nicolaidis, Raymaker, Kapp, Baggs, Ashkenazy, McDonald, Weiner, Maslak, Hunter and Joyce2019). Despite positive intent, majority group researchers have historically produced biased scholarship on novel marginalized populations (Colella et al., Reference Colella, Hebl and King2017). As all research includes some subjective bias, neurotypical researchers are likely to publish information that further marginalizes neurodivergentFootnote2 people as they inherently do not have the lived experience of being neurodivergent themselves. Researchers should include the perspectives of the members of the populations they are conducting research on and aim to support neurodivergent voices. We recommend that researchers (a) include neurodivergent research team membersFootnote3 when researching neurodiversity and (b) strengthen the marginalized participant impact on research findings through methods like qualitative and participatory action research, especially if including neurodivergent research team members is not feasible despite legitimate attempts to do so

    Attributable costs of enterococcal bloodstream infections in a nonsurgical hospital cohort

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    BACKGROUND: Vancomycin-resistant enterococcal (VRE) bloodstream infections (BSI) are associated with increased morbidity and mortality. OBJECTIVE: To determine the attributable costs of vancomycin-sensitive (VSE) and VRE BSI and the independent impact of vancomycin-resistance on hospital costs. METHODS: A retrospective cohort study was conducted of 21,154 non-surgical patients admitted to an academic medical center between 2002 and 2003. Using administrative data, attributable hospital costs (inflation adjusted to 2007)andlengthofstaywereestimatedwithmultivariategeneralizedleastsquares(GLS)modelsandpropensityscorematchedpairs.RESULTS:Thecohortincluded182VSEand94VREBSIcases.Afteradjustmentfordemographics,comorbidities,procedures,nonenterococcalBSI,andearlymortality,theattributablecostsofVSEBSIwere2007) and length of stay were estimated with multivariate generalized least squares (GLS) models and propensity score matched-pairs. RESULTS: The cohort included 182 VSE and 94 VRE BSI cases. After adjustment for demographics, comorbidities, procedures, non-enterococcal BSI, and early mortality, the attributable costs of VSE BSI were 2,250 (95% confidence interval [CI], 1,7581,758–2,880) in the standard GLS model and 2,023(952,023 (95% CI, 1,588–2,575)inthepropensityscoreweightedGLSmodelandtheattributablecostsofVREBSIwere2,575) in the propensity-score weighted GLS model and the attributable costs of VRE BSI were 4,479 (95% CI, 3,5003,500–5,732) in the standard GLS model and 4,036(954,036 (95% CI, 3,170–5,140)inthepropensityscoreweightedGLSmodel.Themedianofthedifferenceincostsbetweenmatchedpairswas5,140) in the propensity-score weighted GLS model. The median of the difference in costs between matched-pairs was 5,282 (2,0422,042–8,043) for VSE BSI and 9,949(959,949 (95% CI, 1,579–24,693)forVREBSI.Theattributablecostsofvancomycinresistancewere24,693) for VRE BSI. The attributable costs of vancomycin-resistance were 1,713 (95% CI, 1,3381,338–2,192) in the standard GLS model and 1,546(951,546 (95% CI, 1,214–$1,968) in the propensity-score weighted GLS model. Attributable length of stay ranged from 1.1–2.2 days for VSE BSI and 2.2–3.5 days for VRE BSI cases. CONCLUSIONS: VSE and VRE BSI were independently associated with hospital costs and length of stay. Vancomycin-resistance was associated with increased costs

    The Remote Learning Experience at Portland State University in Spring 2020

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    It is an endeavor to understand what we have and will learn about the impact of remote instruction on faculty, students and relevant academic support teams. Simply put: We want to learn from an experiment foisted upon us by a health crisis. We have engaged in an incredibly innovative response. And now, we ask what have we learned? How might we improve? And, most importantly, are there implications from this experiment for the future of instruction at PSU and throughout higher education? The project was organized around two stages in the Spring 2020 term. Stage One: Out of the Gate: Reflections and Lessons Learned (First half of the term) Stage Two: Reaching the Finish Line: Lessons Learned and Recommendations for moving forward (Second half of the term). The project began the week of April 20 and continued through June 12. The original plan called for the following participants: (a) ten undergraduate students to put together a group of 8-10 other students to discuss the questions posed in the study; (b) Three graduate students who would assemble 5-7 fellow graduate students; (c) Three tenured or tenure-track faculty, two non-tenure-track faculty and three adjunct faculty, each of whom would form a chat group of 5-7 other faculty to discuss the questions posed in the study. In addition, Judith Ramaley put together a chat group of a dozen student support unit leaders to explore how each unit adjusted as the university moved quickly to remote learning and remote work and then, in a second round, what lessons each had learned throughout the spring term about ways to support students and assist faculty members who were also seeking to help their students

    Resting state network profiles of Alzheimer disease and frontotemporal dementia: A preliminary examination

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    OBJECTIVES/SPECIFIC AIMS: Recent evidence from resting-state fMRI studies have shown that brain network connectivity is altered in patients with neurodegenerative disorders. However, few studies have examined the complete connectivity patterns of these well-reported RSNs using a whole brain approach and how they compare between dementias. Here, we used advanced connectomic approaches to examine the connectivity of RSNs in Alzheimer disease (AD), Frontotemporal dementia (FTD), and age-matched control participants. METHODS/STUDY POPULATION: In total, 44 participants [27 controls (66.4±7.6 years), 13 AD (68.5.63±13.9 years), 4 FTD (59.575±12.2 years)] from an ongoing study at Indiana University School of Medicine were used. Resting-state fMRI data was processed using an in-house pipeline modeled after Power et al. (2014). Images were parcellated into 278 regions of interest (ROI) based on Shen et al. (2013). Connectivity between each ROI pair was described by Pearson correlation coefficient. Brain regions were grouped into 7 canonical RSNs as described by Yeo et al. (2015). Pearson correlation values were then averaged across pairs of ROIs in each network and averaged across individuals in each group. These values were used to determine relative expression of FC in each RSN (intranetwork) and create RSN profiles for each group. RESULTS/ANTICIPATED RESULTS: Our findings support previous literature which shows that limbic networks are disrupted in FTLD participants compared with AD and age-matched controls. In addition, interactions between different RSNs was also examined and a significant difference between controls and AD subjects was found between FP and DMN RSNs. Similarly, previous literature has reported a disruption between executive (frontoparietal) network and default mode network in AD compared with controls. DISCUSSION/SIGNIFICANCE OF IMPACT: Our approach allows us to create profiles that could help compare intranetwork FC in different neurodegenerative diseases. Future work with expanded samples will help us to draw more substantial conclusions regarding differences, if any, in the connectivity patterns between RSNs in various neurodegenerative diseases

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    ECMO for COVID-19 patients in Europe and Israel

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    Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
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