33 research outputs found

    Effect of temperature on the durability of class C fly ash belite cement in simulated radioactive liquid waste: Synergy of chloride and sulphate ions

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    The durability of class C fly ash belite cement (FABC-2-W) in simulated radioactive liquid waste (SRLW) rich in a mixed sodium chloride and sulphate solution is presented here. The effect of the temperature and potential synergic effect of chloride and sulfate ions are discussed. This study has been carried out according to theKoch–Steinegger test, at the temperature of 20 ◦Cand 40 ◦Cduring a period of 180days. The durability has been evaluated by the changes of the flexural strength of mortar, fabricatedwith this cement, immersed in a simulated radioactive liquid waste rich in sulfate (0.5 M), chloride (0.5M) and sodium (1.5M) ions – catalogued like severely aggressive for the traditional Portland cement – and demineralised water, which was used as reference. The reaction mechanism of sulphate, chloride and sodium ions with the mortar was evaluated by scanning electron microscopy (SEM), porosity and pore-size distribution, and X-ray diffraction (XRD). The results showed that the chloride binding and formation of Friedel’s salt was inhibited by the presence of sulphate. Sulphate ion reacts preferentially with the calcium aluminate hydrates forming non-expansive ettringite which precipitated inside the pores; the microstructure was refined and the mechanical properties enhanced. This process was faster and more marked at 40 ◦C

    Toward a 21st-century health care system: Recommendations for health care reform

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    The coverage, cost, and quality problems of the U.S. health care system are evident. Sustainable health care reform must go beyond financing expanded access to care to substantially changing the organization and delivery of care. The FRESH-Thinking Project (www.fresh-thinking.org) held a series of workshops during which physicians, health policy experts, health insurance executives, business leaders, hospital administrators, economists, and others who represent diverse perspectives came together. This group agreed that the following 8 recommendations are fundamental to successful reform: 1. Replace the current fee-for-service payment system with a payment system that encourages and rewards innovation in the efficient delivery of quality care. The new payment system should invest in the development of outcome measures to guide payment. 2. Establish a securely funded, independent agency to sponsor and evaluate research on the comparative effectiveness of drugs, devices, and other medical interventions. 3. Simplify and rationalize federal and state laws and regulations to facilitate organizational innovation, support care coordination, and streamline financial and administrative functions. 4. Develop a health information technology infrastructure with national standards of interoperability to promote data exchange. 5. Create a national health database with the participation of all payers, delivery systems, and others who own health care data. Agree on methods to make de-identified information from this database on clinical interventions, patient outcomes, and costs available to researchers. 6. Identify revenue sources, including a cap on the tax exclusion of employer-based health insurance, to subsidize health care coverage with the goal of insuring all Americans. 7. Create state or regional insurance exchanges to pool risk, so that Americans without access to employer-based or other group insurance could obtain a standard benefits package through these exchanges. Employers should also be allowed to participate in these exchanges for their employees' coverage. 8. Create a health coverage board with broad stakeholder representation to determine and periodically update the affordable standard benefit package available through state or regional insurance exchanges

    Physiologically Based Pharmacokinetics of Molecular Imaging Nanoparticles for mRNA Detection Determined in Tumor-Bearing Mice

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    Disease detection and management might benefit from external imaging of disease gene mRNAs. Previously we designed molecular imaging nanoparticles (MINs) based on peptide nucleic acids complementary to cancer gene mRNAs. The MINs included contrast agents and analogs of insulin-like growth factor 1 (IGF-1). Analysis of MIN tumor uptake data showed stronger binding in tumors than in surrounding tissues. We hypothesized that MINs with an IGF-1 analog stay in circulation by binding to IGF-binding proteins. To test that hypothesis, we fit the tissue distribution results of several MINs in xenograft-bearing mice to a physiological pharmacokinetics model. Fitting experimental tissue distribution data to model-predicted mass transfer of MINs from blood into organs and tumors converged only when the parameter for MINs bound to circulating IGF-binding proteins was set to 10%–20% of the injected MIN dose. This result suggests that previous mouse imaging trials used more MINs than necessary. This prediction can be tested by a ramp of decreasing doses

    Measuring Social Health Following Pediatric Critical Illness: A Scoping Review and Conceptual Framework

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    Objective: Social health is an important component of recovery following critical illness as modeled in the pediatric Post-Intensive Care Syndrome framework. We conducted a scoping review of studies measuring social outcomes (measurable components of social health) following pediatric critical illness and propose a conceptual framework of the social outcomes measured in these studies. Data sources: PubMed, EMBASE, PsycINFO, CINAHL, and the Cochrane Registry Study selection: We identified studies evaluating social outcomes in pediatric intensive care unit (PICU) survivors or their families from 1970–2017 as part of a broader scoping review of outcomes after pediatric critical illness. Data extraction: We identified articles by dual review and dual-extracted study characteristics, instruments, and instrument validation and administration information. For instruments used in studies evaluating a social outcome, we collected instrument content and described it using qualitative methods adapted to a scoping review. Data synthesis: Of 407 articles identified in the scoping review, 223 (55%) evaluated a social outcome. The majority were conducted in North America and the United Kingdom, with wide variation in methodology and population. Among these studies, 38 unique instruments were used to evaluate a social outcome. Specific social outcomes measured included individual (independence, attachment, empathy, social behaviors, social cognition, and social interest), environmental (community perceptions and environment), and network (activities and relationships) characteristics, together with school and family outcomes. While many instruments assessed more than one social outcome, no instrument evaluated all areas of social outcome. Conclusions: The full range of social outcomes reported following pediatric critical illness were not captured by any single instrument. The lack of a comprehensive instrument focused on social outcomes may contribute to under-appreciation of the importance of social outcomes and their under-representation in PICU outcomes research. A more comprehensive evaluation of social outcomes will improve understanding of overall recovery following pediatric critical illness.</p
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