28 results on '"Lemieux, V."'
Search Results
2. Program esilence 1.0 - self-regulation program in food education via instagram-loricorps, study protocol.
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Lemieux, V., Monthuy-Blanc, J., and Moreau, N.
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RESEARCH protocols , *NUTRITION , *COMMUNITIES , *TECHNOLOGICAL innovations , *DATA analysis - Abstract
Introduction: Social medias are seen as a risk factor for mental health because they increase body dissatisfaction and decrease selfesteem. This program is based on alimentation and physical wellbeing by relying on integrated intuitive eating and physical selfesteem. This program, implemented in a community setting use social media (i.e. Instagram-Loricorps), is composed of 12 monthly 180-second video capsule that address themes related to the promotion of body sensations and intuitive movement. Objectives: The main objective of this study is to evaluate the effects of the program into the physical environment targeting the physical self-perceptions (PSP). Specifically, this study evaluates whether the eSILENCE 1.0 Program improves the level of PSP related to nutrition and explores the changes in the level and variability of the PSP. Methods: This project is a mixed sequential explanatory study. 300 participants (Experimental Group [EG; N=200], Control Group [CG; N=100]) are targeted. Online nomothetic questionnaires evaluate occupational changes and PSP in relation to alimentation and are completed by the EG and the CG at pre-test, mid-test and post-test. Online idiographic questionnaires assess PSP and are completed by the EG before and after each video capsule and by the CG once a month without viewing the capsules. Following a preliminary analysis, a focus group will be formed to explain and deepen these results. Participants (N=5) will be recruited voluntarily into the EG. Results: to come. Conclusions: Analysis of quantitative data will be used to assess the effectiveness of the program and analysis of qualitative data will provide an in-depth understanding of the linkages between the variables. [ABSTRACT FROM AUTHOR]
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- 2021
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3. Coalition theory as a framework for understanding and implementing intersectoral health-related interventions.
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O'Neill, M, Lemieux, V, Groleau, G, Frotin, F-P, and Lamarche, PA
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COALITIONS , *PUBLIC health , *HEALTH promotion - Abstract
Offers a working definition of intersectoral action and explores the usefulness of coalition theory as a theoretical framework through which to understand intersectoral health-related action theoretically and practically. Review of related literature; Types of health-related intersectoral actions; Provincial coalition of public health agencies.
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- 1997
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4. What the silence prevention program can do about physical self-perception fluctuation among high school students?
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Lemieux, V. and Monthuy-Blanc, J.
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HIGH school students , *PHYSICAL education teachers , *PHYSICAL fitness , *SELF-perception , *PERCEPTUAL disorders , *FOOD habits - Abstract
Introduction: Students with obesity associated with eating disorders experience disruption, mainly in their physical self-perception (PSP), such as self-esteem. This perceptual disorder plays a central role in the emergence of inappropriate attitude and eating behaviours (IAEB) among overweight students. Very few IAEB and obesity prevention programs are implemented in Canada. None of these programs evaluate PSPs with an idiographic approach to assess PSPs fluctuations. Objectives: The objective of this study is to compare the instantaneous evolution of the PSPs between students aged 11 to 14 engaged in the Silence prevention program (EG2-Silence) compared to students engaged solely in an IAEB prevention program (EG1). Methods: All scales of the Body Dissatisfaction Questionnaire (i.e. perceived body, desired body and body dissatisfaction) and the Physical Self-Inventory - short version (i.e. global self-esteem, perceived physical value, sports skills, physical strength, physical endurance and physical appearance) are evaluated once a week using a weekly logbook. Results:Apositive, but not significant, trend is observed in improving the time series level of the EG2-Silence for multiple PSPs (i.e., for overall self-esteem, perceived physical value, physical condition, perceived physical appearance, perceived body, desired body and body dissatisfaction). Results demonstrate a significantly greater PSP time series instability for the EG2-Silence in two of the three instability indices (i.e., standard deviation and range). Conclusions: The Silence program increases the instability of the time series of the PSPs and has a positive trend in terms of improving the time series level of the PSPs. Future studies should take account integration of IEAB/obesity in transdisciplinary perspective. [ABSTRACT FROM AUTHOR]
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- 2020
5. Visualizing an information assurance risk taxonomy.
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Lemieux, V., Endicott-Popovsky, B., Eckler, K., Dang, T., and Jansen, A.
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- 2011
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6. Molecular Switches for Photorelease.
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Lemieux, V., Gauthier, S., and Branda, N.R.
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- 2007
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7. Virtual Photovoice With Older Adults: Methodological Reflections during the COVID-19 Pandemic.
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Ferlatte O, Karmann J, Gariépy G, Frohlich KL, Moullec G, Lemieux V, and Hébert R
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Photovoice is a participatory action research method in which participants take and narrate photographs to share their experiences and perspectives. This method is gaining in popularity among health researchers. Few studies, however, have described virtual photovoice data collection despite the growing interest among qualitative health researchers for online data collection. As such, the aim of this article is to discuss the implementation of a virtual photovoice study and presents some of the challenges of this design and potential solutions. The study examined issues of social isolation and mental health among older adults during the COVID-19 pandemic in the Canadian province of Québec. Twenty-six older adults took photographs depicting their experience of the pandemic that were then shared in virtual discussion groups. In this article, we discuss three key challenges arising from our study and how we navigated them. First, we offer insights into managing some of the technical difficulties related to using online meeting technologies. Second, we describe the adjustments we made during our study to foster and maintain positive group dynamics. Third, we share our insights into the process of building and maintaining trust between both researchers and participants, and amongst participants. Through a discussion of these challenges, we offer suggestions to guide the work of health promotion researchers wishing to conduct virtual photovoice studies, including with older adults., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)
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- 2022
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8. Leveraging Blockchain-Based Archival Solutions for Sensitive Documentation: a Xinjiang Case Study.
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Hellstern R, Park DC, Lemieux V, and Salimjan G
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This exploratory research surveys scholarly literature on decentralized storage solutions, including theories and works of archival science, and similar applications in humanitarian contexts, to illustrate the necessity of these systems in Xinjiang Uyghur Autonomous Region in China. Xinjiang has recently shifted into the spotlight of the international press for allegations of abuse and forced labor, coercive cultural assimilation, and the creation of a police state. The leadership of the People's Republic of China (PRC) justifies the existence of these training facilities and expansive surveillance networks as part of the PRC-backed efforts to de-radicalize ethnic groups in the region. However, many governments and scholars rebuke these justifications, arguing that these centers are state-run facilities that house extrajudicially detained individuals based on their ethnic identity and religious belief. This paper aims at limiting the plausible deniability of violations conducive to cultural genocide, thus improving the prospects for deterrence and accountability through decentralized evidence management. The technological sophistication of the regime in Xinjiang is outpacing centralized systems and rendering storage solutions hosting evidence of these violations obsolete. This jeopardizes the prospect of truth and reconciliation in the future and allows the party to craft and disseminate their narrative globally with little resistance. Major findings focus on how decentralized systems can improve the streamlining and hosting of evidence regarding human rights violations occurring as well as advancing the study of cryptographic management of evidence regarding the treatment of vulnerable communities in low-rights regions., Competing Interests: Conflict of InterestThe authors declare no competing interests., (© The Author(s), under exclusive licence to Springer Nature B.V. 2022.)
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- 2022
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9. Incisional paresthesia following clavicle plate fixation: does it matter to patients?
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Lemieux V, Afsharpour S, Nam D, and Elmaraghy A
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- Bone Plates adverse effects, Fracture Fixation, Internal adverse effects, Humans, Paresthesia epidemiology, Paresthesia etiology, Retrospective Studies, Treatment Outcome, Clavicle surgery, Fractures, Bone epidemiology, Fractures, Bone surgery
- Abstract
Background: Operative management of clavicle fractures is increasingly common. In the context of explaining the risks and benefits of surgery, understanding the impact of incisional numbness as it relates to the patient experience is key to shared decision making. This study aims to determine the prevalence, extent, and recovery of sensory changes associated with supraclavicular nerve injury after open reduction and plate internal fixation of middle or lateral clavicle shaft fractures., Methods: Eighty-six patients were identified retrospectively and completed a patient experience survey assessing sensory symptoms, perceived post-operative function, and satisfaction. Correlations between demographic factors and outcomes, as well as subgroup analyses were completed to identify factors impacting patient satisfaction., Results: Ninety percent of patients experienced sensory changes post-operatively. Numbness was the most common symptom (64%) and complete resolution occurred in 32% of patients over an average of 19 months. Patients who experienced burning were less satisfied overall with the outcome of their surgery whereas those who were informed of the risk of sensory changes pre-operatively were more satisfied overall., Conclusions: Post-operative sensory disturbance is common. While most patients improve, some symptoms persist in the majority of patients without significant negative effects on satisfaction. Patients should always be advised of the risk of persistent sensory alterations around the surgical site to increase the likelihood of their satisfaction post-operatively., (© 2021. The Author(s).)
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- 2021
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10. Consumers' Intentions to Adopt Blockchain-Based Personal Health Records and Data Sharing: Focus Group Study.
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Lu C, Batista D, Hamouda H, and Lemieux V
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Background: Although researchers are giving increased attention to blockchain-based personal health records (PHRs) and data sharing, the majority of research focuses on technical design. Very little is known about health care consumers' intentions to adopt the applications., Objective: This study aims to explore the intentions and concerns of health care consumers regarding the adoption of blockchain-based personal health records and data sharing., Methods: Three focus groups were conducted, in which 26 participants were shown a prototype of a user interface for a self-sovereign blockchain-based PHR system (ie, a system in which the individual owns, has custody of, and controls access to their personal health information) to be used for privacy and secure health data sharing. A microinterlocutor analysis of focus group transcriptions was performed to show a descriptive overview of participant responses. NVivo 12.0 was used to code the categories of the responses., Results: Participants did not exhibit a substantial increase in their willingness to become owners of health data and share the data with third parties after the blockchain solution was introduced. Participants were concerned about the risks of losing private keys, the resulting difficulty in accessing care, and the irrevocability of data access on blockchain. They did, however, favor a blockchain-based PHR that incorporates a private key recovery system and offers a health wallet hosted by government or other positively perceived organizations. They were more inclined to share data via blockchain if the third party used the data for collective good and offered participants nonmonetary forms of compensation and if the access could be revoked from the third party., Conclusions: Health care consumers were not strongly inclined to adopt blockchain-based PHRs and health data sharing. However, their intentions may increase when the concerns and recommendations demonstrated in this study are considered in application design., (©Chang Lu, Danielle Batista, Hoda Hamouda, Victoria Lemieux. Originally published in JMIR Formative Research (http://formative.jmir.org), 05.11.2020.)
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- 2020
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11. Spatio-temporal variation in oxidative status regulation in a small mammal.
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Lemieux V, Garant D, Reale D, and Bergeron P
- Abstract
Life-history allocation trade-offs are dynamic over time and space according to the ecological and demographical context. Fluctuations in food availability can affect physiological trade-offs like oxidative status regulation, reflecting the balance between pro-oxidant production and antioxidant capacity. Monitoring the spatio-temporal stability of oxidative status in natural settings may help understanding its importance in ecological and evolutionary processes. However, few studies have yet conducted such procedures in wild populations. Here, we monitored individual oxidative status in a wild eastern chipmunk ( Tamias striatus ) population across the 2017 summer active period and over three study sites. Oxidative damage (MDA: Malondialdehyde levels) and non-enzymatic antioxidant levels (FRAP: Ferric reducing antioxidant power and HASC: Hypochlorous acid shock capacity) were quantified across time and space using assays optimized for small blood volumes. Our results showed an increase in oxidative damage mirrored by a decrease in FRAP throughout the season. We also found different antioxidant levels among our three study sites for both markers. Our results also revealed the effects of sex and body mass on oxidative status. Early in the active season, females and individuals with a greater body mass had higher oxidative damage. Males had higher HASC levels than females throughout the summer. This study shows that oxidative status regulation is a dynamic process that requires a detailed spatial and temporal monitoring to yield a complete picture of possible trade-offs between pro-oxidant production and antioxidant capacity., Competing Interests: Dany Garant is an Academic Editor for PeerJ. The other authors declare that they have no competing interests., (©2019 Lemieux et al.)
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- 2019
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12. Development of small blood volume assays for the measurement of oxidative stress markers in mammals.
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Langille E, Lemieux V, Garant D, and Bergeron P
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- Animals, Antioxidants metabolism, Malondialdehyde metabolism, Oxidation-Reduction, Sciuridae, Spectrophotometry, Biological Assay methods, Biomarkers metabolism, Oxidative Stress physiology
- Abstract
Measuring oxidative stress has become increasingly valuable in ecological studies, especially when different markers are measured on the same individual. However, many of the current methods lack sensitivity for analysis of low blood volume samples, which represent a challenge for longitudinal field studies of small organisms. Small blood volumes can usually only be analysed by using a single assay, therefore providing limited information on individual's oxidative profile. In this study, we used blood collected from a population of wild eastern chipmunks (Tamias striatus) and modified methods presented in the literature to improve analytical selectivity and sensitivity required for small blood volumes. Specifically, we proposed a modified malondialdehyde (MDA) analysis protocol by HPLC and also optimized both the uric acid independent ferric reducing antioxidant power (FRAP) and hypochlorous acid shock capacity (HASC) assays. Development of the three modified methods was achieved with a sensitivity and repeatability that meets standards of field ecology while allowing measurement of all three assays in duplicate using less than 60 μL of plasma. Availability of these tests using small blood volumes will provide ecologists with a more comprehensive portrait of an individual's oxidative profile and a better understanding of its determinants and interactions with the environment., Competing Interests: The authors have declared that no competing interests exist.
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- 2018
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13. Cry6Aa1, a Bacillus thuringiensis nematocidal and insecticidal toxin, forms pores in planar lipid bilayers at extremely low concentrations and without the need of proteolytic processing.
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Fortea E, Lemieux V, Potvin L, Chikwana V, Griffin S, Hey T, McCaskill D, Narva K, Tan SY, Xu X, Vachon V, and Schwartz JL
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- Activation, Metabolic, Animals, Antinematodal Agents chemistry, Antinematodal Agents metabolism, Bacillus thuringiensis Toxins, Bacterial Proteins genetics, Bacterial Proteins metabolism, Coleoptera drug effects, Coleoptera enzymology, Coleoptera growth & development, Digestion, Endotoxins genetics, Endotoxins metabolism, Hemolysin Proteins genetics, Hemolysin Proteins metabolism, Hydrogen-Ion Concentration, Insect Proteins metabolism, Insecticides chemistry, Insecticides metabolism, Kinetics, Larva drug effects, Larva enzymology, Larva growth & development, Membrane Fusion drug effects, Microvilli chemistry, Microvilli enzymology, Peptide Hydrolases metabolism, Porosity drug effects, Proteolysis, Recombinant Proteins metabolism, Recombinant Proteins pharmacology, Solubility, Antinematodal Agents pharmacology, Bacillus thuringiensis metabolism, Bacterial Proteins pharmacology, Endotoxins pharmacology, Hemolysin Proteins pharmacology, Insecticides pharmacology, Lipid Bilayers chemistry
- Abstract
Cry6Aa1 is a Bacillus thuringiensis ( Bt ) toxin active against nematodes and corn rootworm insects. Its 3D molecular structure, which has been recently elucidated, is unique among those known for other Bt toxins. Typical three-domain Bt toxins permeabilize receptor-free planar lipid bilayers (PLBs) by forming pores at doses in the 1-50 μg/ml range. Solubilization and proteolytic activation are necessary steps for PLB permeabilization. In contrast to other Bt toxins, Cry6Aa1 formed pores in receptor-free bilayers at doses as low as 200 pg/ml in a wide range of pH (5.5-9.5) and without the need of protease treatment. When Cry6Aa1 was preincubated with Western corn rootworm (WCRW) midgut juice or trypsin, 100 fg/ml of the toxin was sufficient to form pores in PLBs. The overall biophysical properties of the pores were similar for all three forms of the toxin (native, midgut juice- and trypsin-treated), with conductances ranging from 28 to 689 pS, except for their ionic selectivity, which was slightly cationic for the native and midgut juice-treated Cry6Aa1, whereas dual selectivity (to cations or anions) was observed for the pores formed by the trypsin-treated toxin. Enrichment of PLBs with WCRW midgut brush-border membrane material resulted in a 2000-fold reduction of the amount of native Cry6Aa1 required to form pores and affected the biophysical properties of both the native and trypsin-treated forms of the toxin. These results indicate that, although Cry6Aa1 forms pores, the molecular determinants of its mode of action are significantly different from those reported for other Bt toxins., (© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.)
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- 2017
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14. β-Estradiol results in a proprotein convertase subtilisin/kexin type 9-dependent increase in low-density lipoprotein receptor levels in human hepatic HuH7 cells.
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Starr AE, Lemieux V, Noad J, Moore JI, Dewpura T, Raymond A, Chrétien M, Figeys D, and Mayne J
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- Cell Line drug effects, Dose-Response Relationship, Drug, Estradiol pharmacology, Hep G2 Cells drug effects, Hepatocytes drug effects, Hepatocytes metabolism, Humans, Proprotein Convertase 9, Proprotein Convertases genetics, Receptors, LDL genetics, Serine Endopeptidases genetics, Up-Regulation drug effects, Estradiol metabolism, Proprotein Convertases metabolism, Receptors, LDL metabolism, Serine Endopeptidases metabolism
- Abstract
The lower risk of coronary artery disease in premenopausal women than in men and postmenopausal women implicates sex steroids in cardioprotective processes. β-Estradiol upregulates liver low-density lipoprotein receptor (LDLR), which, in turn, decreases circulating levels of low-density lipoprotein, which is a risk factor for coronary artery disease. Conversely, LDLR protein is negatively regulated by proprotein convertase subtilisin/kexin type 9 (PCSK9). Herein, we investigated PCSK9 regulation by β-estradiol and its impact on LDLR in human hepatocarcinoma HuH7 cells grown in the presence or absence of β-estradiol. Immunoblot analysis showed upregulation of LDLR at 3 μm β-estradiol (140%), and the upregulation reached 220% at 10 μm β-estradiol; only at the latter dose was an increase in LDLR mRNA detected by qPCR, suggesting post-translational regulation of LDLR. No changes in PCSK9 mRNA or secreted protein levels were detected by qPCR or ELISA, respectively. β-estradiol-conditioned medium devoid of PCSK9 failed to upregulate LDLR. Similarly, PCSK9 knockdown cells showed no upregulation of LDLR by β-estradiol. Together, these results indicate a requirement for PCSK9 in the β-estradiol-induced upregulation of LDLR. A radiolabeling assay showed a significant, dose-dependent decrease in the ratio of secreted phosphoPCSK9 to total secreted PCSK9 with increasing β-estradiol levels, suggesting a change in the functional state of PCSK9 in the presence of β-estradiol. Our results indicate that the protein upregulation of LDLR at subtranscriptionally effective doses of β-estradiol, and its supratranscriptional upregulation at 10 μm β-estradiol, occur through an extracellular PCSK9-dependent mechanism., (© 2015 The Authors. FEBS Journal published by John Wiley & Sons Ltd on behalf of FEBS.)
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- 2015
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15. Electrostatic assembly of binary nanoparticle superlattices using protein cages.
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Kostiainen MA, Hiekkataipale P, Laiho A, Lemieux V, Seitsonen J, Ruokolainen J, and Ceci P
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- Bromovirus chemistry, Ferritins chemistry, Ferritins ultrastructure, Gold chemistry, Metal Nanoparticles chemistry, Microscopy, Electron, Transmission, Models, Molecular, Nanostructures ultrastructure, Particle Size, RNA, Viral chemistry, Static Electricity, Archaeal Proteins chemistry, Archaeal Proteins ultrastructure, Metal Nanoparticles ultrastructure, Nanostructures chemistry, Nanotechnology instrumentation, Nanotechnology methods
- Abstract
Binary nanoparticle superlattices are periodic nanostructures with lattice constants much shorter than the wavelength of light and could be used to prepare multifunctional metamaterials. Such superlattices are typically made from synthetic nanoparticles, and although biohybrid structures have been developed, incorporating biological building blocks into binary nanoparticle superlattices remains challenging. Protein-based nanocages provide a complex yet monodisperse and geometrically well-defined hollow cage that can be used to encapsulate different materials. Such protein cages have been used to program the self-assembly of encapsulated materials to form free-standing crystals and superlattices at interfaces or in solution. Here, we show that electrostatically patchy protein cages--cowpea chlorotic mottle virus and ferritin cages--can be used to direct the self-assembly of three-dimensional binary superlattices. The negatively charged cages can encapsulate RNA or superparamagnetic iron oxide nanoparticles, and the superlattices are formed through tunable electrostatic interactions with positively charged gold nanoparticles. Gold nanoparticles and viruses form an AB(8)(fcc) crystal structure that is not isostructural with any known atomic or molecular crystal structure and has previously been observed only with large colloidal polymer particles. Gold nanoparticles and empty or nanoparticle-loaded ferritin cages form an interpenetrating simple cubic AB structure (isostructural with CsCl). We also show that these magnetic assemblies provide contrast enhancement in magnetic resonance imaging.
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- 2013
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16. Protocol for the preparation of stimuli-responsive gold nanoparticles capped with elastin-based pentapeptides.
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Lemieux V, Adams PH, and van Hest JC
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- Magnetic Resonance Spectroscopy, Elastin chemistry, Gold chemistry, Metal Nanoparticles chemistry, Oligopeptides chemistry
- Abstract
Stimuli-responsive materials are playing an increasingly important role in a wide range of applications such as drug delivery, diagnostics, sensors, and tissue engineering. Among them, gold nanoparticles responding to changes in their surrounding environment are of particular interest due to their size-related optical properties. Here, we present a novel strategy for the preparation of gold nanoparticles exhibiting a stimuli-responsive behavior. We rely on the use of a ligand consisting of only a single repeat of the elastin-based pentapeptide VPGVG. In this contribution, we describe a protocol for the solid-phase peptide synthesis of thiol-terminated VPGVG ligand, and for the preparation of gold nanoparticles covered with the pentapeptide through a ligand-exchange reaction.
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- 2013
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17. Variations in patients' assessment of chronic illness care across organizational models of primary health care: a multilevel cohort analysis.
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Lévesque JF, Feldman DE, Lemieux V, Tourigny A, Lavoie JP, and Tousignant P
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- Aged, Arthritis psychology, Arthritis therapy, Chronic Disease psychology, Cohort Studies, Community Health Centers standards, Delivery of Health Care, Integrated standards, Diabetes Mellitus psychology, Diabetes Mellitus therapy, Family Practice standards, Female, Group Practice standards, Heart Failure psychology, Heart Failure therapy, Humans, Interviews as Topic, Male, Primary Health Care standards, Pulmonary Disease, Chronic Obstructive psychology, Pulmonary Disease, Chronic Obstructive therapy, Quebec, Surveys and Questionnaires, Chronic Disease therapy, Patient Satisfaction, Primary Health Care methods
- Abstract
Purpose: To measure patients' assessment of chronic illness care and its variation across primary healthcare (PHC) models., Methods: We recruited 776 patients with diabetes, heart failure, arthritis or chronic obstructive pulmonary disease from 33 PHC clinics. Face-to-face interviews, followed by a telephone interview at 12 months, were conducted using the Patient Assessment of Chronic Illness Care (PACIC). Multilevel regression was used in the analysis., Results: The mean PACIC score was low at 2.5 on a scale of 1 to 5. PACIC scores were highest among patients affiliated with family medicine groups (mean, 2.78) and lowest for contact models (mean, 2.35). Patients with arthritis and older persons generally reported a lower assessment of chronic care., Conclusion: Family medicine groups represent an integrated model of PHC associated with higher levels of achievement in chronic care. Variations across PHC organizations suggest that some models are more appropriate for improving management of chronic illness., (Copyright © 2012 Longwoods Publishing.)
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- 2012
18. Catalysis through temporary intramolecularity: mechanistic investigations on aldehyde-catalyzed Cope-type hydroamination lead to the discovery of a more efficient tethering catalyst.
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Guimond N, MacDonald MJ, Lemieux V, and Beauchemin AM
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- Amination, Amines chemistry, Catalysis, Aldehydes chemistry, Allyl Compounds chemistry, Hydroxylamines chemistry
- Abstract
Mechanistic investigations on the aldehyde-catalyzed intermolecular hydroamination of allylic amines using N-alkylhydroxylamines are presented. Under the reaction conditions, the presence of a specific aldehyde catalyst allows formation of a mixed aminal intermediate, which permits intramolecular Cope-type hydroamination. The reaction was determined to be first-order in both the aldehyde catalyst (α-benzyloxyacetaldehyde) and the allylic amine. However, the reaction displays an inverse order behavior in benzylhydroxylamine, which reveals a significant off-cycle pathway and highlights the importance of an aldehyde catalyst that promotes a reversible aminal formation. Kinetic isotope effect experiments suggest that hydroamination is the rate-limiting step of this catalytic cycle. Overall, these results enabled the elaboration of a more accurate catalytic cycle and led to the development of a more efficient catalytic system for alkene hydroamination. The use of 5-10 mol % of paraformaldehyde proved more effective than the use of 20 mol % of α-benzyloxyacetaldehyde, leading to high yields of intermolecular hydroamination products within 24 h at 30 °C.
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- 2012
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19. Hydrogen bonding directed intermolecular Cope-type hydroamination of alkenes.
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Zhao SB, Bilodeau E, Lemieux V, and Beauchemin AM
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- Amination, Hydrogen chemistry, Hydrogen Bonding, Molecular Structure, Oxidation-Reduction, Alkenes chemistry
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Intermolecular hydroamination of unactivated alkenes represents a significant synthetic challenge. An efficient Cope-type hydroamination is achieved under mild conditions for reactions of N-alkylhydroxylamines with allylic amines, using hydrogen bonding to achieve increased reactivity and high regioselectivity. This approach provides a number of highly functionalized vicinal diamine motifs as Markovnikov addition products.
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- 2012
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20. Using light and a molecular switch to 'lock' and 'unlock' the Diels-Alder reaction.
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Erno Z, Asadirad AM, Lemieux V, and Branda NR
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Light is used to 'gate' the Diels-Alder reaction using a photoresponsive dithienylfuran backbone and turn the reversibility of the Diels-Alder reaction 'off' and 'on' at 100 °C. These features make the reported system an excellent candidate for developing the next generation of self-healing polymers and photothermal drug delivery vehicles., (This journal is © The Royal Society of Chemistry 2012)
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- 2012
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21. Primary Healthcare Organization and Quality-of-Life Outcomes for Persons with Chronic Disease.
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Feldman DE, Lévesque JF, Lemieux V, Tourigny A, Lavoie JP, and Tousignant P
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Purpose: To explore the association between primary healthcare (PHC) organizational model and health-related quality of life (HRQoL) in persons with chronic disease., Methods: We recruited 776 patients with a primary diagnosis of one of four chronic diseases from 33 PHC clinics. Patients were interviewed at baseline, 6, 12 and 18 months. We categorized PHC model by administrative type and by a taxonomy according to organizational attributes. HRQoL was measured by disease-specific questionnaires., Results: Mean age was 67 years and 55.3% were female. PHC models differed with respect to case mix: community models served older patients with higher co-morbidity and lower health status. Multilevel logistic regression revealed that none of the PHC organizational models was associated with HRQoL. Having fewer co-morbidities, higher self-rated health and not using home care services were associated with higher HRQoL., Conclusion: Despite their having patients with more complex health problems, HRQoL in patients of community practices was equivalent to that of patients in other types of PHC organizations.
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- 2012
22. Are primary healthcare organizational attributes associated with patient self-efficacy for managing chronic disease?
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Lemieux V, Lévesque JF, and Ehrmann-Feldman D
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Our objective was to explore how individual and primary healthcare (PHC) organizational attributes influence patients' ability in chronic illness self-management. We conducted a cohort study, recruiting 776 adults with chronic disease from 33 PHC settings in the province of Quebec. Organizational data on the PHC clinics were obtained from a prior study. Participants were interviewed at baseline, 6 and 12 months, responding to questionnaires on self-efficacy, health status, socio-demographics, healthcare use and experience of care. Multilevel modelling showed that 52.5% of the variance in self-efficacy occurs at the level of the individual and 4.0% at the organizational level. Controlling for diagnosis, patient factors associated with self-efficacy were self-rated health (B coeff 0.76: CI 0.60; 0.92), concurrent depression (B coeff -1.41: CI 1.96; -0.86) and satisfaction with care (B coeff 0.27: CI 0.15; 0.39). None of the organizational attributes was significantly associated with self-efficacy after adjusting for lower-level variables. Patients generally reported receiving little self-management teaching across organizations.
- Published
- 2011
23. Elastin-based stimuli-responsive gold nanoparticles.
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Lemieux V, Adams PH, and van Hest JC
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Gold nanoparticles covered with ligands consisting of only a single repeat of the elastin-based pentapeptide VPGVG exhibit a stimuli-responsive behaviour.
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- 2010
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24. Modulating the Lewis acidity of boron using a photoswitch.
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Lemieux V, Spantulescu MD, Baldridge KK, and Branda NR
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- 2008
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25. Selective and sequential photorelease using molecular switches.
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Lemieux V, Gauthier S, and Branda NR
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- Molecular Structure, Polycyclic Compounds chemistry, Sensitivity and Specificity, Photochemistry methods
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- 2006
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26. Reactivity-gated photochromism of 1,2-dithienylethenes for potential use in dosimetry applications.
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Lemieux V and Branda NR
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- Colorimetry, Cyclization, Molecular Structure, Photochemistry, Bridged Bicyclo Compounds chemical synthesis, Bridged Bicyclo Compounds chemistry, Butadienes chemistry, Thiophenes chemical synthesis, Thiophenes chemistry
- Abstract
[reaction: see text] A novel molecular switching system based on reactivity-gated photochromism operates because a butadiene undergoes a [4 + 2] cycloaddition reaction with a dienophile to produce the photoresponsive 1,2-dithienylethene backbone. The reversible change in color when samples are irradiated with appropriate wavelengths of light occurs only after the Diels-Alder cycloaddition reaction takes place.
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- 2005
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27. Comparison of some effects of dipyridamole and adenosine on thrombus formation, platelet adhesiveness and blood pressure in rabbits and rats.
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Philp RB and Lemieux V
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- Animals, Blood Coagulation, Male, Rabbits, Rats, Blood Platelets metabolism, Blood Pressure drug effects, Nucleosides pharmacology, Pyridinium Compounds pharmacology, Thrombosis etiology
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- 1968
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28. Effects of dipyridamole and nitroprusside on the oxygen paradox and reactive hyperemia.
- Author
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Lemieux VP, Gowdey CW, and Philp RB
- Subjects
- Animals, Blood Pressure drug effects, Carotid Arteries, Cats, Femoral Artery, Hypoxia, Nucleosides blood, Pressoreceptors drug effects, Regional Blood Flow drug effects, Vascular Resistance drug effects, Dipyridamole pharmacology, Ferricyanides pharmacology, Hyperemia, Hypotension etiology, Oxygen blood, Vasodilator Agents pharmacology
- Published
- 1970
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