3,303 research outputs found

    Cyclic-RGD Peptides Increase the Adenoviral Transduction of Human Mesenchymal Stem Cells

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    Human mesenchymal stem cells (hMSCs) have been extensively explored for drug delivery applications due to their safety, immunomodulatory properties, and ability to differentiate into new tissues. The experiments presented in this study were designed to determine peptide-based mechanisms to increase the adenoviral transduction of hMSCs for the purpose of improving their capacity as drug delivery vehicles. Specifically, we demonstrated that cyclic- RGD peptides increased the internalization of adenoviruses into MSCs. MSCs treated with cyclic-RGD peptides had a transduction efficiency of 76.6%±4%, which was significantly greater than the 23.5%±12.2% transduction efficiency of untreated stem cells (P<0.05). Blocking endocytosis with inhibitors of dynamin or actin polymerization decreased the cyclic-RGD-mediated increase in transduction efficiency. MSCs treated with cyclic-RGD and adenoviruses carrying the gene for bone morphogenetic protein-2 produced significantly greater concentrations of this growth factor compared to stem cells treated with only adenoviruses or adenoviruses cocultured with cyclic-RAD peptides. Furthermore, this stem cell-produced bone morphogenetic protein induced alkaline phosphatase expression in C2C12 cells indicating growth factor bioactivity. Taken together, these studies suggest that cyclic-RGD peptides could be used to increase the adenoviral transduction of hMSCs and increase their therapeutic potential.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140200/1/scd.2012.0379.pd

    Development and Validation of Preenlistment Screening Composites for Army Enlisted Personnel

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    Prepared for: US Army Recruiting Command Program Analysis and Evaluation Directorate Research and Studies Divisionhttp://archive.org/details/developmentvalid56zimmNAN

    Results from the third Scottish National Prevalence Survey: is a population health approach now needed to prevent healthcare-associated infections?

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    Summary Background Healthcare associated infections (HAI) are a major public health concern and a significant cause of morbidity and mortality. A robust and current evidence base that is specific to local, national and Europe-wide settings is necessary to inform the development of strategies to reduce HAI and contain antimicrobial resistance (AMR). Aim To measure the prevalence of HAI and antimicrobial prescribing and identify key priority areas for interventions to reduce the burden of infection. Methods A national rolling PPS in National Health Service (NHS) acute, NHS non-acute, NHS paediatric and independent hospitals was carried out between September and November 2016 using the European Centre for Disease Prevention and Control protocol designed for the European PPS. Findings The prevalence of HAI was 4.6%, 2.7% and 3.2% in acute adults, paediatric and non-acute patient groups, respectively. The most common HAI types reported in adult patients were urinary tract infection and pneumonia. The prevalence of antimicrobial prescribing was 35.7%, 29.3% and 13.8% in acute adults, paediatric and non-acute patient groups, respectively. Respiratory, skin and soft tissue, gastrointestinal and urinary tract infections were the most common infections being treated at the time of survey. Conclusion HAI continues to be a public health concern in Scotland. UTI and pneumonia continue to place a significant burden on patients and on healthcare delivery, including those that develop in the community and require hospital admission. A broader population health approach which focuses on reducing the risk of infection upstream would reduce these infections in both community and hospital settings

    Valence band offset of InN/AlN heterojunctions measured by X-ray photoelectron spectroscopy

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    The valence band offset of wurtzite-InN/AlN (0001) heterojunctions is determined by x-ray photoelectron spectroscopy to be 1.52±0.17 eV. Together with the resulting conduction band offset of 4.0±0.2 eV, a type-I heterojunction forms between InN and AlN in the straddling arrangement

    Surface electronic properties of undoped InAlN alloys

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    The variation in surface electronic properties of undoped c-plane InxAl1−xN alloys has been investigated across the composition range using a combination of high-resolution x-ray photoemission spectroscopy and single-field Hall effect measurements. For the In-rich alloys, electron accumulation layers, accompanied by a downward band bending, are present at the surface, with a decrease to approximately flatband conditions with increasing Al composition. However, for the Al-rich alloys, the undoped samples were found to be insulating with approximate midgap pinning of the surface Fermi level observed

    Method Effects in IS Survey Research: An Assessment and Recommendations

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    Issues involving method effects are routinely taught to PhD students in Information Systems (IS). Unfortunately, the results of an assessment of a population of 128 survey-based studies published in three top IS journals over a six-year period (1999-2005) reveal that relatively little attention is being paid to method bias and that the threat of serious method bias is great in many of the published studies. For instance, even the best-understood variety of method bias--common source bias--is found to have gone unnoted in over one-third of the papers that used a single respondent for all construct measures for reasons other than necessity. This study was motivated by studies in other areas of the social sciences which have resulted in calls for areas such as IS to conduct empirical assessments of the frequency of the various forms of method bias. Here, the myriad sources of method bias are reviewed and methods for minimizing or eliminating method effects, both in the design of a study and in the subsequent analysis of the data, are discussed. Data on the frequency of appearance of a wide variety of potential sources of method bias are provided and conclusions are drawn. A series of recommendations is made concerning creating greater awareness of method bias on the part of the IS research community and greater use of method bias criteria in the screening reviews of papers that are done by IS journals

    Thresholds, breakpoints, and nonlinearity in freshwaters as related to management.

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    Nonlinear ecological responses to anthropogenic forcing are common, and in some cases, the ecosystem responds by assuming a new stable state. This article is an overview and serves as the introduction to several articles in this BRIDGES cluster that are directed toward managers interested in dealing with nonlinear responses in freshwaters, particularly streams. A threshold or breakpoint occurs where the system responds rapidly to a relatively small change in a driver. The existence of a threshold can signal a change in system configuration to an alternative stable state, although such a change does not occur with all thresholds. In general, a mechanistic understanding of ecological dynamics is required to predict thresholds, where they will occur, and if they are associated with the occurrence of alternative stable states. Thresholds are difficult to predict, although a variety of univariate methods has been used to indicate thresholds in ecological data. When we applied several methods to one type of response variable, the resulting threshold values varied 3-fold, indicating that more research on detection methods is necessary. Numerous case studies suggest that the threshold concept is important in all ecosystems. Managers should be aware that human actions might result in undesirable rapid changes and potentially an unwanted alternative stable state, and that recovery from that state might require far more resources and time than avoiding entering the state in the first place would have required. Given the difficulties in predicting thresholds and alternative states, the precautionary approach to ecosystem management is probably the most prudent
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