55 research outputs found

    Heparan sulfate regulates amyloid precursor protein processing by BACE1, the Alzheimer's β-secretase

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    Cleavage of amyloid precursor protein (APP) by the Alzheimer's β-secretase (BACE1) is a key step in generating amyloid β-peptide, the main component of amyloid plaques. Here we report evidence that heparan sulfate (HS) interacts with β-site APP-cleaving enzyme (BACE) 1 and regulates its cleavage of APP. We show that HS and heparin interact directly with BACE1 and inhibit in vitro processing of peptide and APP substrates. Inhibitory activity is dependent on saccharide size and specific structural characteristics, and the mechanism of action involves blocking access of substrate to the active site. In cellular assays, HS specifically inhibits BACE1 cleavage of APP but not alternative cleavage by α-secretase. Endogenous HS immunoprecipitates with BACE1 and colocalizes with BACE1 in the Golgi complex and at the cell surface, two of its putative sites of action. Furthermore, inhibition of cellular HS synthesis results in enhanced BACE1 activity. Our findings identify HS as a natural regulator of BACE1 and suggest a novel mechanism for control of APP processing

    Sistema de medición basado en los modelos de Visuales y Malca para lograr eficacia en la responsabilidad social empresarial ambiental del Hiper Mercado Plaza Vea de Chiclayo 2009-2010

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    A lo largo de las últimas décadas ante los cambios económicos y globales observados dentro del proceso de globalización es que se visualiza un nuevo concepto de negocio que actualmente la sociedad exige, por eso el presente trabajo aborda las relaciones existentes entre la empresa, sus públicos interesados (stakeholders) y el instinto de desarrollo sustentable y social, en dicho proceso se incorporan valores y nuevos programas, haciendo un enfoque nuevo de una perspectiva a largo plazo que evidencie no solo la formación de valor para los accionistas y la empresa sino también para el conjunto de redes sociales que están unidos directa o indirectamente. En este trabajo de investigación estudiaremos los problemas que envuelven los stakeholders, que son colaboradores, proveedores, socios, los productos y servicios que se ofertan, si son nocivos o no, la creación de empleos, capacitación ambiental, salud, seguridad laboral y programas de promoción a través de los medios de comunicación, partiendo de este punto para llegar al objetivo que es medir y diagnosticar la responsabilidad social empresarial en la empresa Plaza Vea Chiclayo, basándonos en las teorías de Malca y Visuales. Es decisión de la empresa introducir en su gestión empresarial nuestro enfoque presentado en la investigación, como parte de su filosofía, visión y al transmitirla a la sociedad, la empresa presentará una ventaja competitiva sobre las otras que operan en el mercado.Tesi

    Irreversible proliferation of magnetic moments at cleaved surfaces of the topological Kondo insulator SmB6

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    The compound SmB6_6 is the best established realization of a topological Kondo insulator, in which a topological insulator state is obtained through Kondo coherence. Recent studies have found evidence that the surface of SmB6_6 hosts ferromagnetic domains, creating an intrinsic platform for unidirectional ballistic transport at the domain boundaries. Here, surface-sensitive X-ray absorption (XAS) and bulk-sensitive resonant inelastic X-ray scattering (RIXS) spectra are measured at the Sm N4,5_{4,5}-edge, and used to evaluate electronic symmetries, excitations and temperature dependence near the surface of cleaved samples. The XAS data show that the density of large-moment atomic multiplet states on a cleaved surface grows irreversibly over time, to a degree that likely exceeds a related change that has recently been observed in the surface 4f orbital occupation

    A practical tool for managing change: cross-sectional psychometric assessment of the safe surgery organizational readiness tool

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    Background: Strengthening health systems through planned safety and quality improvement initiatives is an imperative to achieve more equitable, resilient, and effective care. And yet, years of organizational behavior research demonstrate that change initiatives often fall short because managers fail to account for organizational readiness for change. This finding remains true especially among surgical safety and quality improvement initiatives in low-income countries and middle-income countries. In this study, our aim was to psychometrically assess the construct validity and internal consistency of the Safe Surgery Organizational Readiness Tool (SSORT), a short survey tool designed to provide change leaders with insight into facility infrastructure that supports learning and readiness to undertake change. Materials and methods: To demonstrate generalizability and achieve a large sample size (n=1706) to conduct exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), a collaboration between seven surgical and anesthesia safety and quality improvement initiatives was formed. Collected survey data from health care workers were divided into pilot, exploration, and confirmation samples. The pilot sample was used to assess feasibility. The exploration sample was used to conduct EFA, while the confirmation sample was used to conduct CFA. Factor internal consistency was assessed using Cronbach’s alpha coefficient. Results: Results of the EFA retained 9 of the 16 proposed factors associated with readiness to change. CFA results of the identified 9 factor model, measured by 28 survey items, demonstrated excellent fit to data. These factors (appropriateness, resistance to change, team efficacy, team learning orientation, team valence, communication about change, learning environment, vision for sustainability, and facility capacity) were also found to be internally consistent. Conclusion: Our findings suggest that communication, team learning, and supportive environment are components of change readiness that can be reliably measured prior to implementation of projects that promote surgical safety and quality improvement in low-income countries and middle-income countries. Future research can link performance on identified factors to outcomes that matter most to patients

    Phenotype of ARDS alveolar and blood neutrophils

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    RATIONALE: Acute respiratory distress syndrome is refractory to pharmacological intervention. Inappropriate activation of alveolar neutrophils is believed to underpin this disease's complex pathophysiology, yet these cells have been little studied. OBJECTIVES: To examine the functional and transcriptional profiles of patient blood and alveolar neutrophils compared with healthy volunteer cells, and to define their sensitivity to phosphoinositide 3-kinase inhibition. METHODS: Twenty-three ventilated patients underwent bronchoalveolar lavage. Alveolar and blood neutrophil apoptosis, phagocytosis, and adhesion molecules were quantified by flow cytometry, and oxidase responses were quantified by chemiluminescence. Cytokine and transcriptional profiling were used in multiplex and GeneChip arrays. MEASUREMENTS AND MAIN RESULTS: Patient blood and alveolar neutrophils were distinct from healthy circulating cells, with increased CD11b and reduced CD62L expression, delayed constitutive apoptosis, and primed oxidase responses. Incubating control cells with disease bronchoalveolar lavage recapitulated the aberrant functional phenotype, and this could be reversed by phosphoinositide 3-kinase inhibitors. In contrast, the prosurvival phenotype of patient cells was resistant to phosphoinositide 3-kinase inhibition. RNA transcriptomic analysis revealed modified immune, cytoskeletal, and cell death pathways in patient cells, aligning closely to sepsis and burns datasets but not to phosphoinositide 3-kinase signatures. CONCLUSIONS: Acute respiratory distress syndrome blood and alveolar neutrophils display a distinct primed prosurvival profile and transcriptional signature. The enhanced respiratory burst was phosphoinositide 3-kinase-dependent but delayed apoptosis and the altered transcriptional profile were not. These unexpected findings cast doubt over the utility of phosphoinositide 3-kinase inhibition in acute respiratory distress syndrome and highlight the importance of evaluating novel therapeutic strategies in patient-derived cells.This work was funded by a non-commercial grant from GSK, with additional support from The Wellcome Trust, Papworth Hospital, The British Lung Foundation and the NIHR Cambridge Biomedical Research Centre. DMLS holds a Gates Cambridge Scholarship; CS is in receipt of a Wellcome Trust Early Postdoctoral Research Fellowship for Clinician Scientists [WT101692MA].This is the author accepted manuscript. The final version is available from ATS Journals via http://dx.doi.org/10.1164/rccm.201509-1818O

    Photo-ionization and fragmentation of Sc3N@C80 following excitation above the Sc K-edge

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    We have investigated the ionization and fragmentation of a metallo-endohedral fullerene, Sc3N@C80, using ultrashort (10 fs) x-ray pulses. Following selective ionization of a Sc (1s) electron (hν = 4.55 keV), an Auger cascade leads predominantly to either a vibrationally cold multiply charged parent molecule or multifragmentation of the carbon cage following a phase transition. In contrast to previous studies, no intermediate regime of C2 evaporation from the carbon cage is observed. A time-delayed, hard x-ray pulse (hν = 5.0 keV) was used to attempt to probe the electron transfer dynamics between the encapsulated Sc species and the carbon cage. A small but significant change in the intensity of Sc-containing fragment ions and coincidence counts for a delay of 100 fs compared to 0 fs, as well as an increase in the yield of small carbon fragment ions, may be indicative of incomplete charge transfer from the carbon cage on the sub-100 fs time scale

    Extreme Conservation Leads to Recovery of the Virunga Mountain Gorillas

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    As wildlife populations are declining, conservationists are under increasing pressure to measure the effectiveness of different management strategies. Conventional conservation measures such as law enforcement and community development projects are typically designed to minimize negative human influences upon a species and its ecosystem. In contrast, we define “extreme” conservation as efforts targeted to deliberately increase positive human influences, including veterinary care and close monitoring of individual animals. Here we compare the impact of both conservation approaches upon the population growth rate of the critically endangered Virunga mountain gorillas (Gorilla beringei beringei), which increased by 50% since their nadir in 1981, from approximately 250 to nearly 400 gorillas. Using demographic data from 1967–2008, we show an annual decline of 0.7%±0.059% for unhabituated gorillas that received intensive levels of conventional conservation approaches, versus an increase 4.1%±0.088% for habituated gorillas that also received extreme conservation measures. Each group of habituated gorillas is now continuously guarded by a separate team of field staff during daylight hours and receives veterinary treatment for snares, respiratory disease, and other life-threatening conditions. These results suggest that conventional conservation efforts prevented a severe decline of the overall population, but additional extreme measures were needed to achieve positive growth. Demographic stochasticity and socioecological factors had minimal impact on variability in the growth rates. Veterinary interventions could account for up to 40% of the difference in growth rates between habituated versus unhabituated gorillas, with the remaining difference likely arising from greater protection against poachers. Thus, by increasing protection and facilitating veterinary treatment, the daily monitoring of each habituated group contributed to most of the difference in growth rates. Our results argue for wider consideration of extreme measures and offer a startling view of the enormous resources that may be needed to conserve some endangered species

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Sistema de medición basado en los modelos de Visuales y Malca para lograr eficacia en la responsabilidad social empresarial ambiental del Hiper Mercado Plaza Vea de Chiclayo 2009-2010

    Get PDF
    TesisA lo largo de las últimas décadas ante los cambios económicos y globales observados dentro del proceso de globalización es que se visualiza un nuevo concepto de negocio que actualmente la sociedad exige, por eso el presente trabajo aborda las relaciones existentes entre la empresa, sus públicos interesados (stakeholders) y el instinto de desarrollo sustentable y social, en dicho proceso se incorporan valores y nuevos programas, haciendo un enfoque nuevo de una perspectiva a largo plazo que evidencie no solo la formación de valor para los accionistas y la empresa sino también para el conjunto de redes sociales que están unidos directa o indirectamente. En este trabajo de investigación estudiaremos los problemas que envuelven los stakeholders, que son colaboradores, proveedores, socios, los productos y servicios que se ofertan, si son nocivos o no, la creación de empleos, capacitación ambiental, salud, seguridad laboral y programas de promoción a través de los medios de comunicación, partiendo de este punto para llegar al objetivo que es medir y diagnosticar la responsabilidad social empresarial en la empresa Plaza Vea Chiclayo, basándonos en las teorías de Malca y Visuales. Es decisión de la empresa introducir en su gestión empresarial nuestro enfoque presentado en la investigación, como parte de su filosofía, visión y al transmitirla a la sociedad, la empresa presentará una ventaja competitiva sobre las otras que operan en el mercado
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