1,025 research outputs found

    Cytoplasmic expression systems triggered by mRNA yield increased gene expression in post-mitotic neurons

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    Non-viral vectors are promising vehicles for gene therapy but delivery of plasmid DNA to post-mitotic cells is challenging as nuclear entry is particularly inefficient. We have developed and evaluated a hybrid mRNA/DNA system designed to bypass the nuclear barrier to transfection and facilitate cytoplasmic gene expression. This system, based on co-delivery of mRNA(A64) encoding for T7 RNA polymerase (T7 RNAP) with a T7-driven plasmid, produced between 10- and 2200-fold higher gene expression in primary dorsal root ganglion neuronal (DRGN) cultures isolated from Sprague–Dawley rats compared to a cytomegalovirus (CMV)-driven plasmid, and 30-fold greater expression than the enhanced T7-based autogene plasmid pR011. Cell-free assays and in vitro transfections highlighted the versatility of this system with small quantities of T7 RNAP mRNA required to mediate expression at levels that were significantly greater than with the T7-driven plasmid alone or supplemented with T7 RNAP protein. We have also characterized a number of parameters, such as mRNA structure, intracellular stability and persistence of each nucleic acid component that represent important factors in determining the transfection efficiency of this hybrid expression system. The results from this study demonstrate that co-delivery of mRNA is a promising strategy to yield increased expression with plasmid DNA, and represents an important step towards improving the capability of non-viral vectors to mediate efficient gene transfer in cell types, such as in DRGN, where the nuclear membrane is a significant barrier to transfection

    Giant magnetothermopower of magnon-assisted transport in ferromagnetic tunnel junctions

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    We present a theoretical description of the thermopower due to magnon-assisted tunneling in a mesoscopic tunnel junction between two ferromagnetic metals. The thermopower is generated in the course of thermal equilibration between two baths of magnons, mediated by electrons. For a junction between two ferromagnets with antiparallel polarizations, the ability of magnon-assisted tunneling to create thermopower SAPS_{AP} depends on the difference between the size Π↑,↓\Pi_{\uparrow, \downarrow} of the majority and minority band Fermi surfaces and it is proportional to a temperature dependent factor (kBT/ωD)3/2(k_{B}T/\omega_{D})^{3/2} where ωD\omega_{D} is the magnon Debye energy. The latter factor reflects the fractional change in the net magnetization of the reservoirs due to thermal magnons at temperature TT (Bloch's T3/2T^{3/2} law). In contrast, the contribution of magnon-assisted tunneling to the thermopower SPS_P of a junction with parallel polarizations is negligible. As the relative polarizations of ferromagnetic layers can be manipulated by an external magnetic field, a large difference ΔS=SAP−SP≈SAP∼−(kB/e)f(Π↑,Π↓)(kBT/ωD)3/2\Delta S = S_{AP} - S_P \approx S_{AP} \sim - (k_B/e) f (\Pi_{\uparrow},\Pi_{\downarrow}) (k_BT/\omega_{D})^{3/2} results in a magnetothermopower effect. This magnetothermopower effect becomes giant in the extreme case of a junction between two half-metallic ferromagnets, ΔS∼−kB/e\Delta S \sim - k_B/e.Comment: 9 pages, 4 eps figure

    School factors as barriers to and facilitators of a preventive intervention for pediatric type 2 diabetes

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    School-based interventions are essential to prevent pediatric obesity and type 2 diabetes. School environmental factors influence implementation of these interventions. This article examines how school factors acted as barriers to and facilitators of the HEALTHY intervention. The HEALTHY study was a cluster-randomized trial of a multicomponent intervention implemented in 21 schools. Interview data were analyzed to identify barriers and facilitators. Barriers included teacher frustration that intervention activities detracted from tested subjects, student resistance and misbehavior, classroom management problems, communication equipment problems, lack of teacher/staff engagement, high cost and limited availability of nutritious products, inadequate facility space, and large class sizes. Facilitators included teacher/staff engagement, effective classroom management, student engagement, schools with direct control over food service, support from school leaders, and adequate facilities and equipment. Contextual barriers and facilitators must be taken into account in the design and implementation of school-based health interventions

    Understanding the identity of lived experience researchers and providers: a conceptual framework and systematic narrative review

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    Background: Identity is how we understand ourselves and others through the roles or social groups we occupy. This review focuses on lived experience researchers and providers and the impact of these roles on identity. Lived experience researchers and providers use their lived experience of mental or physical disability either as experts by experience, researchers, peer workers, or mental health professionals with lived experience. They must navigate both professional and personal aspects to their roles which can be complex. Performing roles simultaneously embodying professional and lived experiences contribute towards a lack of clarity to identity. This is not adequately explained by the theoretical evidence base for identity. Main body: This systematic review and narrative synthesis aimed to provide a conceptual framework to understand how identity of lived experience researchers and providers is conceptualised. A search strategy was entered into EBSCO to access Academic search complete, CINAHL, MEDLINE, PsycINFO, Psych Articles, and Connected papers. Out of the 2049 yielded papers, thirteen qualitative papers were eligible and synthesised, resulting in a conceptual framework. Five themes explained identity positions: Professional, Service user, Integrated, Unintegrated and Liminal. The EMERGES framework, an original conception of this review, found themes of: Enablers and Empowerment, Motivation, Empathy of the self and others, Recovery model and medical model, Growth and transformation, Exclusion and Survivor roots contributed to lived experience researcher and provider identities. Conclusions: The EMERGES framework offers a novel way to understand the identities of lived experience researchers and providers, helping support effective team working in mental health, education, and research settings

    Plasma Dynamics

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    Contains research objectives and summary of research on twenty-one projects split into three sections, with four sub-sections in the second section and reports on twelve research projects.National Science Foundation (Grant ENG75-06242)U.S. Energy Research and Development Administration (Contract E(11-1)-2766)U.S. Energy Research and Development Agency (Contract E(11-1)-3070)U.S. Energy Research and Development Administration (Contract E(11-1)-3070)Research Laboratory of Electronics, M.I.T. Industrial Fellowshi

    Introducing the New Patient Expectations in Spine Oncology Questionnaire

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    BACKGROUND AND OBJECTIVES: It has been hypothesized that a discrepancy between pretreatment expectations and perceived outcomes is a significant source of patient dissatisfaction. Currently, there is lack in understanding and tools to assess patient expectations regarding the outcomes of treatment for spinal metastases. The objective of this study was therefore to develop a patient expectations questionnaire regarding the outcomes after surgery and/or radiotherapy for spinal metastases. METHODS: A multiphase international qualitative study was conducted. Phase 1 of the study included semistructured interviews with patients and relatives to understand their expectations of the outcomes of treatment. In addition, physicians were interviewed about their communication practices with patients regarding treatment and expected outcomes. In phase 2, items were developed based on the results of the interviews in phase 1. In phase 3, patients were interviewed to validate the content and language of the questionnaire. Selection of the final items was based on feedback from patients regarding content, language, and relevance. RESULTS: In phase 1, 24 patients and 22 physicians were included. A total of 34 items were developed for the preliminary questionnaire. After phase 3, a total of 22 items were retained for the final version of the questionnaire. The questionnaire is divided into 3 sections: (1) patient expectations regarding treatment outcomes, (2) prognosis, and (3) consultation with the physician. The items cover expectations related to pain, analgesia requirements, daily and physical function, overall quality of life, life expectancy, and information provided by the physician. CONCLUSION: The new Patient Expectations in Spine Oncology questionnaire was developed to evaluate patient expectations regarding the outcomes after treatment for spinal metastases. The Patient Expectations in Spine Oncology questionnaire will allow physicians to systematically assess patient expectations of planned treatment and thus help guide patients toward realistic expectations of treatment outcome
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