259 research outputs found

    Strong Ferromagnetic Exchange Coupling Mediated by a Bridging Tetrazine Radical in a Dinuclear Nickel Complex.

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    The radical bridged compound [(Ni- (TPMA))2-ÎŒ-bmtz‱−](BF4)3·3CH3CN (bmtz = 3,6-bis- (2â€Č-pyrimidyl)-1,2,4,5-tetrazine, TPMA = tris(2- pyridylmethyl)amine) exhibits strong ferromagnetic exchange between the S = 1 NiII centers and the bridging S = 1/2 bmtz radical with J = 96 ± 5 cm−1 (−2JNi‑radSNiSrad). DFT calculations support the existence of strong ferromagnetic exchange.Department of Energy Office of Science Graduate Fellowship, Instituto de Ciencia y Tecnología del Distrito Federal (ICyTDF) National Science Foundation (CHE-1310574) and the Robert A. Welch Foundation (A-1449)

    Influenza virus inoculum volume is critical to elucidate age‐dependent mortality in mice

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    The elderly exhibit increased mortality to influenza viral infection for unclear reasons. Mice are frequently used to model how aging impacts disease. Several studies have shown that aged mice exhibit an increased mortality to influenza virus, but two recent studies demonstrated the opposite. These two studies administered the virus intranasally in 20 ”L, whereas the other studies used a viral inoculum in at least 30 ”L. To determine whether the volume of the inoculum could explain the conflicting reports, we infected young and aged mice via intranasal instillation of 40 ”L or 20 ”L containing 1 x 104 plaque‐forming units (PFU) of H1N1 influenza virus. We found that intranasal administration of 40 ”L but not 20 ”L of inoculum resulted in age‐dependent mortality in mice. Compared to aged mice infected with 40 ”L inoculum, those infected with 20 ”L inoculum showed reduced levels of live virus and IFN‐ÎČ in the lung 3 days postinfection. Furthermore, aged mice administered 40 ”L of Evans blue intranasally displayed increased dye retention in their bronchoalveolar lavage fluid compared to those administered 20 ”L of Evans blue. Our data demonstrate that the inoculating volume of virus is critical for adequate delivery of influenza virus to the lung and thus for efficient infection of aged mice. These findings shed light on discrepant results in the literature regarding aged mice and influenza infection, and establish that mice can be used to examine how aging impacts the response to this biomedically important infection.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148415/1/acel12893.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148415/2/acel12893_am.pd

    Sustainable soil improvement and water use inagriculture: CCU enabling technologies afford an innovative approach

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    With industrial CO2-emission reduction the heart of carbon capture enabling technologies, we report on a solution engineered to potentially redress the issues of soil improvement and sustainable use of fresh water for food production. In a laboratory-scale pilot study, we demonstrate the capabilities of an innovative and novel product utilising carbon-capture to restore soil properties critical for crop production. In the first study of its kind, the carbon-initiated mode-of-action resulted in changes to soil physical and chemical properties. Soil water retention in a range of soil types was significantly increased by up to 62%; soil pH increased by 0.7–1.1 units: soil microbial colonisation increased by ˜20% over the short term and crop biomass was enhanced by up to 38%. These results give impetus for developing CCU technologies to address environmental issues

    One-Year Consumption of a Mediterranean-Like Dietary Pattern With Vitamin D3 Supplements Induced Small Scale but Extensive Changes of Immune Cell Phenotype, Co-receptor Expression and Innate Immune Responses in Healthy Elderly Subjects:Results From the United Kingdom Arm of the NU-AGE Trial

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    Amongst the major features of aging are chronic low grade inflammation and a decline in immune function. The Mediterranean diet (MedDiet) is considered to be a valuable tool to improve health status, and although beneficial effects have been reported, to date, immunological outcomes have not been extensively studied. We aimed to test the hypothesis that 1 year of a tailored intervention based on the MedDiet with vitamin D (10 ÎŒg/day) would improve innate immune responses in healthy elderly subjects (65–79 years) from the English cohort (272 subjects recruited) of the NU-AGE randomized, controlled study (clinicaltrials.gov, NCT01754012). Of the 272 subjects forming the United Kingdom cohort a subgroup of 122 subjects (61 in the intervention group and 61 in the control group) was used to evaluate ex vivo innate immune response, phenotype of circulating immune cells, and levels of pro- and anti-inflammatory markers. Odds Ratio (OR) was calculated for all the parameters analyzed. After adjustment by gender, MedDiet-females with a BMI < 31 kg/m2 had a significant upregulation of circulating CD40+CD86+ cells (OR 3.44, 95% CI 1.01–11.75, P = 0.0437). Furthermore, in all MedDiet subjects, regardless of gender, we observed a MedDiet-dependent changes, although not statistically significant of immune-critical parameters including T cell degranulation, cytokine production and co-receptor expression. Overall, our study showed that adherence to an individually tailored Mediterranean-like dietary pattern with a daily low dose of vitamin D3 supplements for 1 year modified a large variety of parameters of immune function in healthy, elderly subjects. We interpreted these data as showing that the MedDiet in later life could improve aspects of innate immunity and thus it could aid the design of strategies to counteract age-associated disturbances

    Nutrition, diet and immunosenescence

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    Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly

    Role of neutrophils in CVB3 infection and viral myocarditis

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    Coxsackievirus B3 (CVB3) is a globally prevalent enterovirus of the Picornaviridae family that is frequently associated with viral myocarditis (VM). Neutrophils, as first responders, may be key cells in determining viral disease outcomes; however, neutrophils have been poorly studied with respect to viral infection. Although neutrophils have been ascribed a relevant role in early cardiac inflammation, their precise role in CVB3 infection has not yet been evaluated. In this study, we aimed to determine if the interaction between human neutrophils and CVB3 could lead to viral replication and/or modulation of neutrophil survival and biological functions, and whether neutrophil depletion in a murine model has a beneficial or harmful effect on CVB3 infection. Our results show that CVB3 interacted with but did not replicate in human neutrophils. Neutrophils recognized CVB3 mainly through endosomal TLR-8, and infection triggered NFÎșB activation. Virus internalization resulted in increased cell survival, up-regulation of CD11b, enhanced adhesion to fibrinogen and fibronectin, and the secretion of IL-6, IL-1ÎČ, TNF-α, and IL-8. Supernatants from infected neutrophils exerted chemotactic activity partly mediated by IL-8. The infected neutrophils released myeloperoxidase and triggered neutrophil extracellular trap formation in the presence of TNF-α. In mice infected with CVB3, viral RNA was detected in neutrophils as well as in mononuclear cells. After neutrophil depletion, mice showed reduced VM reflected by a reduction in viral titers, cell exudates, and CCL-2 mRNA levels, as well as the abrogation of reactive cardiomyocyte hypertrophy. Our results indicate that neutrophils have relevant direct and indirect roles in the pathogenesis of CVB3-induced VM.Fil: Rivadeneyra, Leonardo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: CharĂł, Nancy Lorena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Kviatcovsky, Denise. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: de la Barrera, Silvia Susana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gomez, Ricardo Martin. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Schattner, Mirta Ana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

    Scale-dependent perspectives on the geomorphology and evolution of beachdune systems

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    Despite widespread recognition that landforms are complex Earth systems with process-response linkages that span temporal scales from seconds to millennia and spatial scales from sand grains to landscapes, research that integrates knowledge across these scales is fairly uncommon. As a result, understanding of geomorphic systems is often scale-constrained due to a host of methodological, logistical, and theoretical factors that limit the scope of how Earth scientists study landforms and broader landscapes. This paper reviews recent advances in understanding of the geomorphology of beach-dune systems derived from over a decade of collaborative research from Prince Edward Island (PEI), Canada. A comprehensive summary of key findings is provided from short-term experiments embedded within a decade-long monitoring program and a multi-decadal reconstruction of coastal landscape change. Specific attention is paid to the challenges of scale integration and the contextual limitations research at specific spatial and/or temporal scales imposes. A conceptual framework is presented that integrates across key scales of investigation in geomorphology and is grounded in classic ideas in Earth surface sciences on the effectiveness of formative events at different scales. The paper uses this framework to organize the review of this body of research in a 'scale aware' way and, thereby, identifies many new advances in knowledge on the form and function of subaerial beach-dune systems. Finally, the paper offers a synopsis of how greater understanding of the complexities at different scales can be used to inform the development of predictive models, especially those at a temporal scale of decades to centuries, which are most relevant to coastal management issues. Models at this (landform) scale require an understanding of controls that exist at both ‘landscape’ and ‘plot’ scales. Landscape scale controls such as sea level change, regional climate, and the underlying geologic framework essentially provide bounding conditions for independent variables such as winds, waves, water levels, and littoral sediment supply. Similarly, an holistic understanding of the range of processes, feedbacks, and linkages at the finer plot scale is required to inform and verify the assumptions that underly the physical modelling of beach-dune interaction at the landform scale

    Workshop on Immunizations in Older Adults: Identifying Future Research Agendas

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    Goals for immunization in older adults may differ from those in young adults and children, in whom complete prevention of disease is the objective. Often, reduced hospitalization and death but also averting exacerbation of underlying chronic illness, functional decline, and frailty are important goals in the older age group. Because of the effect of age on dendritic cell function, T cell-mediated immune suppression, reduced proliferative capacity of T cells, and other immune responses, the efficacy of vaccines often wanes with advanced age. This article summarizes the discussion and proceedings of a workshop organized by the Association of Specialty Professors, the Infectious Diseases Society of America, the American Geriatrics Society, the National Institute on Aging, and the National Institute of Allergy and Infectious Diseases. Leading researchers and clinicians in the fields of immunology, epidemiology, infectious diseases, geriatrics, and gerontology reviewed the current status of vaccines in older adults, identified knowledge gaps, and suggest priority areas for future research. The goal of the workshop was to identify what is known about immunizations (efficacy, effect, and current schedule) in older adults and to recommend priorities for future research. Investigation in the areas identified has the potential to enhance understanding of the immune process in aging individuals, inform vaccine development, and lead to more-effective strategies to reduce the risk of vaccine-preventable illness in older adults.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79340/1/j.1532-5415.2010.02772.x.pd

    Rejuvenating conventional dendritic cells and T follicular helper cell formation after vaccination.

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    Germinal centres (GCs) are T follicular helper cell (Tfh)-dependent structures that form in response to vaccination, producing long-lived antibody secreting plasma cells and memory B cells that protect against subsequent infection. With advancing age the GC and Tfh cell response declines, resulting in impaired humoral immunity. We sought to discover what underpins the poor Tfh cell response in ageing and whether it is possible to correct it. Here, we demonstrate that older people and aged mice have impaired Tfh cell differentiation upon vaccination. This deficit is preceded by poor activation of conventional dendritic cells type 2 (cDC2) due to reduced type 1 interferon signalling. Importantly, the Tfh and cDC2 cell response can be boosted in aged mice by treatment with a TLR7 agonist. This demonstrates that age-associated defects in the cDC2 and Tfh cell response are not irreversible and can be enhanced to improve vaccine responses in older individuals
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