133 research outputs found
Microbial communities in a former pilot-scale uranium mine in Eastern Finland – Association with radium immobilization
The bacterial, fungal and archaeal communities were characterized in 17 top soil organic and mineral layer samples and in top sediment samples of the Paukkajanvaara area, a former pilot-scale uranium mine, located in Eno, Eastern Finland. using amplicon sequencing and qPCR. Soil and sediment samples were in addition analyzed for (Ra-226), radium sulfate (SO42-), nitrate (NO3-) and phosphate (PO43-) concentrations. New bacterial strains, representing Pseudomonas spp., were isolated from the mine and reference area and used in laboratory experiments on uptake and leaching of radium (Ra). The effect of these strains on the sulfate leaching from the soil samples was also tested in vitro. Between 6 x 10(6) and 5 x 10(8) copies g(-1) DW (dry weight) of bacterial 16S rRNA genes, 5 x 10(5)-1 x 10(8) copies g(-1) DW archaeal 16S rRNA genes and 1 x 10(5)-1 x 10(8) copies g(-1) DW fungal 5.8S rRNA genes were detected in the samples. A total of 814. 54 and 167 bacterial, archaeal and fungal genera. respectively, were identified. Proteobacteria, Euryarchaeota and Mortiriella were the dominant bacterial, archaeal and fungal phyla, respectively. All tested Pseudomonas spp. strains isolates from Paukkajanvaara removed Ra from the solution, but the amount of removed Ra depended on incubation conditions (temperature, time and nutrient broth). The highest removal of Ra (5320 L/kg DW) was observed by the Pseudomonas sp. strain T5-6-I at 37 degrees C. All Pseudomonas spp. strains decreased the release of Ra from soil with an average of 23% while simultaneously increasing the concentration of SO42- in the solution by 11%. As Pseudomonas spp. were frequent in both the sequence data and the cultures, these bacteria may play an important role in the immobilization of Ra in the Paukkajanvaara mine area. (C) 2019 The Authors. Published by Elsevier B.V.Peer reviewe
Évaluation de l’efficacité du programme Global Medical Student Partnership dans les études de médecine de premier cycle
Background: The Global Medical Student Partnership (GMSP) is, a medical student-led international initiative to promote accessible Global Health learning. This study aims to evaluate the effectiveness of the GMSP program in meeting its learning objectives.
Methods: Canadian and international medical student pairs met online monthly (January-May 2018) to discuss global health-related medical cases. Students then reviewed cases with local GMSP peers and faculty experts. A mixed-methods study was performed to evaluate whether the objectives of the program had been achieved. 26 of 32 (81.3%) students completed a questionnaire, and 13 (40.6%) also participated in one-on-one semi-structured interviews. Descriptive statistics and thematic analysis were used to analyze students’ perspectives on skill development through GMSP.
Results: GMSP students agreed or strongly agreed that international collaboration and communication skills were more important to them following program participation (92.3%, 92.3% respectively). Many expressed that after GMSP, they knew more about their healthcare system, practices abroad and how to solve complex health issues (92.3%, 84.6%, 61.5% respectively). Qualitative data showed GMSP improved students’ communication and presentation skills, provided a foundation for international relationships, fostered appraisal of diverse health systems, and furthered students’ understanding of health advocacy.
Conclusions: Our findings demonstrate that GMSP met its original objectives by providing students with opportunities to engage in international collaborations and to further develop their skills in advocacy, communication, and health-systems research. This program may be an important addition to medical education as it makes use of technology and peer-to-peer exchange to enable global health learning.Contexte : Le Global Medical Student Partnership (GMSP) est une initiative d’envergure internationale menée par des étudiants en médecine qui vise à favoriser la formation en santé mondiale. La présente étude consiste à évaluer l’efficacité du programme GMSP pour atteindre ses objectifs d’apprentissage.
Méthodologie : Des paires d’étudiants en médecine canadiens et étrangers se sont rencontrés en ligne tous les mois, entre janvier et mai 2018, pour discuter de situations cliniques en santé mondiale. Après la rencontre, ces situations cliniques ont été revues par des pairs locaux du programme GMSP et des experts du corps professoral. On a effectué une étude à devis mixte pour déterminer si les objectifs du programme avaient été atteints. 26 des 32 (81,3 %) étudiants ont répondu à un questionnaire et 13 (40,6 %) ont aussi pris part à des entrevues individuelles semi-dirigées. Des statistiques descriptives et une analyse thématique ont été utilisées analyser les perceptions des étudiants sur le développement d’habiletés par le programme GMSP.
Résultats : Les étudiants participant au programme GMSP étaient d’accord ou très en accord pour dire que les habiletés à la collaboration internationale et à la communication étaient plus importantes à leurs yeux après la participation au programme (92.3%, 92,3%, respectivement). Bon nombre ont affirmé qu’après le programme GMSP, ils en connaissaient plus sur leur système de soins de santé, les pratiques à l’étranger et les façons de résoudre des problèmes de santé complexes (92,3 %, 84,6 %, 61,5 % respectivement). Des données qualitatives ont montré que le programme GMSP a amélioré les aptitudes à la communication et des techniques de présentation. Elles ont servi à établir des relations à l’international, à évaluer divers systèmes de soins de santé et à mieux comprendre la promotion de la santé et à militer en faveur de celle-ci.
Conclusions : Nos résultats montrent que le programme GMSP a atteint ses objectifs de départ puisqu’il a donné aux étudiants des occasions de collaboration internationale et leur a permis de développer davantage leurs habiletés en matière de défense des droits, de communication, et de recherche sur les systèmes de soins de santé. Ce programme pourrait s’avérer un important complément à la formation médicale parce qu’il utilise la technologie et des échanges pairs-pairs pour l’apprentissage des enjeux de santé mondiaux
Melt Electrowriting of Graded Porous Scaffolds to Mimic the Matrix Structure of the Human Trabecular Meshwork
The permeability of the human trabecular meshwork (HTM) regulates eye pressure via a porosity gradient across its thickness modulated by stacked layers of matrix fibrils and cells. Changes in HTM porosity are associated with increases in intraocular pressure and the progress of diseases such as glaucoma. Engineered HTMs could help to understand the structure-function relation in natural tissues and lead to new regenerative solutions. Here, melt electrowriting (MEW) is explored as a biofabrication technique to produce fibrillar, porous scaffolds that mimic the multilayer, gradient structure of native HTM. Poly(caprolactone) constructs with a height of 125-500 μm and fiber diameters of 10-12 μm are printed. Scaffolds with a tensile modulus between 5.6 and 13 MPa and a static compression modulus in the range of 6-360 kPa are obtained by varying the scaffold design, that is, the density and orientation of the fibers and number of stacked layers. Primary HTM cells attach to the scaffolds, proliferate, and form a confluent layer within 8-14 days, depending on the scaffold design. High cell viability and cell morphology close to that in the native tissue are observed. The present work demonstrates the utility of MEW for reconstructing complex morphological features of natural tissues
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Melt Electrowriting of Scaffolds with a Porosity Gradient to Mimic the Matrix Structure of the Human Trabecular Meshwork
The permeability of the Human Trabecular Meshwork (HTM) regulates eye pressure via a porosity gradient across its thickness modulated by stacked layers of matrix fibrils and cells. Changes in HTM porosity are associated with increases in intraocular pressure and the progress of diseases like glaucoma. Engineered HTMs could help to understand the structure-function relation in natural tissues, and lead to new regenerative solutions. Here, melt electrowriting (MEW) is explored as a biofabrication technique to produce fibrillar, porous scaffolds that mimic the multilayer, gradient structure of native HTM. Poly(caprolactone) constructs with a height of 125-500 μm and fiber diameters of 10-12 μm are printed. Scaffolds with a tensile modulus between 5.6 and 13 MPa, and a static compression modulus in the range of 6-360 kPa are obtained by varying the scaffolds design, i.e., density and orientation of the fibers and number of stacked layers. Primary HTM cells attach to the scaffolds, proliferate, and form a confluent layer within 8-14 days, depending on the scaffold design. High cell viability and cell morphology close to that in the native tissue are observed. The present work demonstrates the utility of MEW to reconstruct complex morphological features of natural tissues
3UCubed: The IMAP Student Collaboration CubeSat Project
The 3UCubed project is a 3U CubeSat being jointly developed by the University of New Hampshire, Sonoma State University, and Howard University as a part of the NASA Interstellar Mapping and Acceleration Probe (IMAP)1 student collaboration. This project consists of a multidisciplinary team of undergraduate students from all three universities. The mission goal of the 3UCubed is to understand how Earth\u27s polar upper atmosphere (‘the thermosphere’ in Earth’s auroral regions) responds to particle precipitation and solar wind forcing and internal magnetospheric processes.
3UCubed includes two instruments with rocket heritage to achieve the science mission: an ultraviolet photomultiplier tube (UV-PMT) and electron retarding potential analyzer (ERPA). The spacecraft bus consists of the following subsystems–Attitude Determination and Control, Command and Data Handling, Power, Communication, Structural, and Thermal.
Currently, the project is in the post-PDR stage, starting to build and test engineering models to develop a FlatSat prior to critical design review in 2023. The goal is to launch at least one 3U CubeSat a to collect science data close to the anticipated peak of Solar Cycle 25 around July 2025.2 Our mother mission–IMAP is also projected to launch in 2025, which will let us jointly analyze the science data of the main mission, providing the solar wind measurements and inputs to the magnetosphere with that of 3UCubed, providing the response of Earth’s cusp to these inputs
Eukaryotic Polyribosome Profile Analysis
Protein synthesis is a complex cellular process that is regulated at many levels. For example, global translation can be inhibited at the initiation phase or the elongation phase by a variety of cellular stresses such as amino acid starvation or growth factor withdrawal. Alternatively, translation of individual mRNAs can be regulated by mRNA localization or the presence of cognate microRNAs. Studies of protein synthesis frequently utilize polyribosome analysis to shed light on the mechanisms of translation regulation or defects in protein synthesis. In this assay, mRNA/ribosome complexes are isolated from eukaryotic cells. A sucrose density gradient separates mRNAs bound to multiple ribosomes known as polyribosomes from mRNAs bound to a single ribosome or monosome. Fractionation of the gradients allows isolation and quantification of the different ribosomal populations and their associated mRNAs or proteins. Differences in the ratio of polyribosomes to monosomes under defined conditions can be indicative of defects in either translation initiation or elongation/termination. Examination of the mRNAs present in the polyribosome fractions can reveal whether the cohort of individual mRNAs being translated changes with experimental conditions. In addition, ribosome assembly can be monitored by analysis of the small and large ribosomal subunit peaks which are also separated by the gradient. In this video, we present a method for the preparation of crude ribosomal extracts from yeast cells, separation of the extract by sucrose gradient and interpretation of the results. This procedure is readily adaptable to mammalian cells
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Design of MARQUIS2: study protocol for a mentored implementation study of an evidence-based toolkit to improve patient safety through medication reconciliation.
BackgroundThe first Multi-center Medication Reconciliation Quality Improvement Study (MARQUIS1) demonstrated that implementation of a medication reconciliation best practices toolkit decreased total unintentional medication discrepancies in five hospitals. We sought to implement the MARQUIS toolkit in more diverse hospitals, incorporating lessons learned from MARQUIS1.MethodsMARQUIS2 is a pragmatic, mentored implementation QI study which collected clinical and implementation outcomes. Sites implemented a revised toolkit, which included interventions from these domains: 1) best possible medication history (BPMH)-taking; 2) discharge medication reconciliation and patient/caregiver counseling; 3) identifying and defining clinician roles and responsibilities; 4) risk stratification; 5) health information technology improvements; 6) improved access to medication sources; 7) identification and correction of real-time discrepancies; and, 8) stakeholder engagement. Eight hospitalists mentored the sites via one site visit and monthly phone calls over the 18-month intervention period. Each site's local QI team assessed opportunities to improve, implemented at least one of the 17 toolkit components, and accessed a variety of resources (e.g. implementation manual, webinars, and workshops). Outcomes to be assessed will include unintentional medication discrepancies per patient.DiscussionA mentored multi-center medication reconciliation QI initiative using a best practices toolkit was successfully implemented across 18 medical centers. The 18 participating sites varied in size, teaching status, location, and electronic health record (EHR) platform. We introduce barriers to implementation and lessons learned from MARQUIS1, such as the importance of utilizing dedicated, trained medication history takers, simple EHR solutions, clarifying roles and responsibilities, and the input of patients and families when improving medication reconciliation
Structural characterization of a tetrametallic diamine-bis(phenolate) complex of lithium and synthesis of a related bismuth complex
A novel lithium complex was prepared from the reaction of 1,4-bis(2-hydroxy-3,5-di-tert-butyl-benzyl)imidazolidine H2[O2N2]BuBuIm (L1H2) with n-butyllithium to provide the corresponding tetralithium amine-bis(phenolate) complex {Li2[L1]}2·4THF, 1. Variable temperature 7Li NMR revealed that this complex is labile in solution, dissociating at elevated temperatures to afford two dilithium entities. Additionally, 7Li MAS NMR was performed on 1 to provide information regarding the lithium coordination environment in the bulk solid-state. The reactivity of 1 was assessed in the ring-expansion polymerization of ε-caprolactone (ε-CL), which was first order in ε-CL with an activation energy of 50.9 kJmol−1. Reaction of 1 and a related Li complex (formed in situ) with BiCl3 afforded hydrolytically unstable bismuth phenolate species, as evidenced by the isolation and structural characterization of [Bi4(Cl)3(μ-Cl)(μ-O)(O)2{[O2N2]BuBuPip}2], 2, where [O2N2]BuBuPip is the homopiperazine-containing analog of L1
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Multi-compartment profiling of cacterial and host metabolites identifies intestinal dysbiosis and its functional consequences in the critically ill child
Adverse physiology and antibiotic exposure devastate the intestinal microbiome in critical illness. Time and cost implications limit the immediate clinical potential of microbial sequencing to identify or treat intestinal dysbiosis. Here, we examined whether metabolic profiling is a feasible method of monitoring intestinal dysbiosis in critically ill children. Prospective multicenter cohort study. Three U.K.-based PICUs. Mechanically ventilated critically ill (n = 60) and age-matched healthy children (n = 55). Collection of urine and fecal samples in children admitted to the PICU. A single fecal and urine sample was collected in healthy controls. Untargeted and targeted metabolic profiling using 1H-nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry or urine and fecal samples. This was integrated with analysis of fecal bacterial 16S ribosomal RNA profiles and clinical disease severity indicators. We observed separation of global urinary and fecal metabolic profiles in critically ill compared with healthy children. Urinary excretion of mammalian-microbial co-metabolites hippurate, 4-cresol sulphate, and formate were reduced in critical illness compared with healthy children. Reduced fecal excretion of short-chain fatty acids (including butyrate, propionate, and acetate) were observed in the patient cohort, demonstrating that these metabolites also distinguished between critical illness and health. Dysregulation of intestinal bile metabolism was evidenced by increased primary and reduced secondary fecal bile acid excretion. Fecal butyrate correlated with days free of intensive care at 30 days (r = 0.38; p = 0.03), while urinary formate correlated inversely with vasopressor requirement (r = -0.2; p = 0.037). Disruption to the functional activity of the intestinal microbiome may result in worsening organ failure in the critically ill child. Profiling of bacterial metabolites in fecal and urine samples may support identification and treatment of intestinal dysbiosis in critical illness.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
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