Surface Modification of Melt Extruded Poly(ε-caprolactone) Nanofibers: Toward a New Scalable Biomaterial Scaffold.

A photochemical modification of melt-extruded polymeric nanofibers is described. A bioorthogonal functional group is used to decorate fibers made exclusively from commodity polymers, covalently attach fluorophores and peptides, and direct cell growth. Our process begins by using a layered coextrusion method, where poly(ε-caprolactone) (PCL) nanofibers are incorporated within a macroscopic poly(ethylene oxide) (PEO) tape through a series of die multipliers within the extrusion line. The PEO layer is then removed with a water wash to yield rectangular PCL nanofibers with controlled cross-sectional dimensions. The fibers can be subsequently modified using photochemistry to yield a "clickable" handle for performing the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction on their surface. We have attached fluorophores, which exhibit dense surface coverage when using ligand-accelerated CuAAC reaction conditions. In addition, an RGD peptide motif was coupled to the surface of the fibers. Subsequent cell-based studies have shown that the RGD peptide is biologically accessible at the surface, leading to increased cellular adhesion and spreading versus PCL control surfaces. This functionalized coextruded fiber has the advantages of modularity and scalability, opening a potentially new avenue for biomaterials fabrication

Preferential Association of Segment Blocks in Polyurethane Nanocomposites

Submitted to MacromoleculesControlling the level of dispersion of silicate layers in polymer matrices through intermolecular interactions and exploiting these interactions to enhance thermomechanical behavior are key challenges in the field of polymer nanocomposites. In this investigation, unmodified Laponite platelets are dispersed in a segmented polyurethane containing polar, hydrophilic soft segments and a hydrophobic hard segment using a novel solvent exchange method and compared to polyurethane nanocomposites containing more hydrophobic hard and soft domains. It was determined that the silicate layers were preferentially, but not exclusively, attracted to the hydrophilic, polar soft domains. An apparent micro-phase segregated morphology was observed in transmission electron microscopy for this system, revealing regions of exfoliation and intercalation. According to polarizing optical microscopy, strain-induced alignment is inhibited for this polyurethane nanocomposite, which is reflected in dramatic reductions in tensile strength and ultimate extensibility. In comparison, the Laponite discs appear to be preferentially, but not exclusively, embedded to the hard domains in the segmented polyurethanes containing more hydrophobic hard and soft domains. Exfoliation of the clay platelets leads to enhanced modulus and toughness without a reduction in extensibility. This study provides clues for exploiting silicate-polymer interactions to tune material properties without chemical modification.Institute for Soldier Nanotechnology (ISN) at MI

The 2016 Academic Emergency Medicine Consensus Conference, Shared Decision Making in the Emergency Department: Development of a Policy-relevant Patient-centered Research Agenda Diagnostic Testing Breakout Session Report.

Diagnostic testing is an integral component of patient evaluation in the emergency department (ED). Emergency clinicians frequently use diagnostic testing to more confidently exclude worst-case diagnoses rather than to determine the most likely etiology for a presenting complaint. Increased utilization of diagnostic testing has not been associated with reductions in disease-related mortality but has led to increased overall healthcare costs and other unintended consequences (e.g., incidental findings requiring further workup, unnecessary exposure to ionizing radiation or potentially nephrotoxic contrast). Shared decision making (SDM) presents an opportunity for clinicians to discuss the benefits and harms associated with diagnostic testing with patients to more closely tailor testing to patient risk. This article introduces the challenges and opportunities associated with incorporating SDM into emergency care by summarizing the conclusions of the diagnostic testing group at the 2016 Academic Emergency Medicine Consensus Conference on SDM. Three primary domains emerged: 1) characteristics of a condition or test appropriate for SDM, 2) critical elements of and potential barriers to SDM discussions on diagnostic testing, and 3) financial aspects of SDM applied to diagnostic testing. The most critical research questions to improve engagement of patients in their acute care diagnostic decisions were determined by consensus

Rising Annual Costs of Dizziness Presentations to U.S. Emergency Departments

Objectives Dizziness and vertigo account for roughly 4% of chief symptoms in the emergency department ( ED ). Little is known about the aggregate costs of ED evaluations for these patients. The authors sought to estimate the annual national costs associated with ED visits for dizziness. Methods This cost study of adult U.S. ED visits presenting with dizziness or vertigo combined public‐use ED visit data (1995 to 2009) from the National Hospital Ambulatory Medical Care Survey ( NHAMCS ) and cost data (2003 to 2008) from the Medical Expenditure Panel Survey ( MEPS ). We calculated total visits, test utilization, and ED diagnoses from NHAMCS . Diagnosis groups were defined using the Healthcare Cost and Utilization Project's Clinical Classifications Software ( HCUP ‐ CCS ). Total visits and the proportion undergoing neuroimaging for future years were extrapolated using an autoregressive forecasting model. The average ED visit cost‐per‐diagnosis‐group from MEPS were calculated, adjusting to 2011 dollars using the Hospital Personal Health Care Expenditures price index. An overall weighted mean across the diagnostic groups was used to estimate total national costs. Year 2011 data are reported in 2011 dollars. Results The estimated number of 2011 US ED visits for dizziness or vertigo was 3.9 million (95% confidence interval [ CI ] = 3.6 to 4.2 million). The proportion undergoing diagnostic imaging by computed tomography ( CT ), magnetic resonance imaging ( MRI ), or both in 2011 was estimated to be 39.9% (39.4% CT , 2.3% MRI ). The mean per‐ ED ‐dizziness‐visit cost was $1,004 in 2011 dollars. The total extrapolated 2011 national costs were$3.9 billion. HCUP ‐ CCS key diagnostic groups for those presenting with dizziness and vertigo included the following (fraction of dizziness visits, cost‐per‐ ED ‐visit, attributable annual national costs): otologic/vestibular (25.7%; $768;$757 million), cardiovascular (16.5%, $1,489;$941 million), and cerebrovascular (3.1%; $1059;$127 million). Neuroimaging was estimated to account for about 12% of the total costs for dizziness visits in 2011 ( CT scans $360 million, MRI scans$110 million). Conclusions Total U.S. national costs for patients presenting with dizziness to the ED are substantial and are estimated to now exceed $4 billion per year (about 4% of total ED costs). Rising costs over time appear to reflect the rising prevalence of ED visits for dizziness and increased rates of imaging use. Future economic studies should focus on the specific breakdown of total costs, emphasizing areas of high cost and use that might be safely reduced. Resumen Incremento Anual de los Costes de las Atenciones por Mareo en los Servicios de Urgencias de Estados Unidos Objectivos El mareo y el vértigo suman aproximadamente el 4% de los motivos de consulta en el servicio de urgencias ( SU ). Se conoce poco sobre los costes globales de las evaluaciones del SU en estos pacientes. Se buscó estimar los costes anuales nacionales asociados con las visitas al SU por mareo. Metodología Este estudio de costes de visitas al SU de adultos norteamericanos que acudieron con mareo o vértigo combinó los datos públicos de las visitas a los SU (1995 a 2009) recogidos por el National Hospital Ambulatory Medical Care Survey ( NHAMCS ) y los costes (2003 a 2008) recogidos por el Medical Expenditure Panel Survey ( MEPS ). Se calcularon el total de visitas, el uso de pruebas diagnósticas y los diagnósticos del SU del NHAMCS . Los grupos diagnósticos se definieron según el Healthcare Cost and Utilization Project's Clinical Classifications Software ( HCUP ‐ CCS ). Los datos del año 2011 se documentaron en dólares de 2011. El total de visitas y la proporción de neuroimagen llevada a cabo en los futuros años se extrapoló usando un modelo predictivo autorregresivo. La media del coste por visita al SU por grupo diagnóstico del MEPS se calculó, ajustándose a dólares de 2011, mediante el índice de precios de los Hospital Personal Health Care Expenditures. Se utilizó una media ponderada global entre los grupos diagnósticos para estimar los costes totales nacionales. Resultados El número de visitas al SU en Estados Unidos en 2011 por mareo o vértigo fue de 3,9 millones ( IC 95% = 3,6 a 4,2 millones). El porcentaje de pruebas diagnósticas de imagen llevadas a cabo por tomografía computarizada ( TC ), resonancia magnética ( RM ) o ambas en 2011 se estimó en un 39,9% (39,4% TC , 2,3% RM ). La media de coste por visita al SU por mareo fue de 1.004 dólares de 2011. Los costes totales, extrapolados para todo el país, fueron de 3.900 millones de dólares. Los grupos diagnósticos HCUP ‐ CCS para aquéllos que presentaron mareo o vértigo incluyeron los siguientes (proporción de visitas por mareo; coste por visita al SU ; costes anuales nacionales atribuibles): otológico/vestibular (25,7%; 768 dólares; 757 millones de dólares), cardiovascular (16,5%, 1.489 dólares; 941 millones de dólares) y cerebrovascular (3,1%; 1.059 dólares; 127 millones de dólares). Se estimó una suma en la neuroimagen del 12% del total de costes para las visitas por mareo en 2011 (360 millones de dólares para la TC y 110 millones de dólares para la RM ). Conclusiones Los costes totales en Estados Unidos para los pacientes que acuden por mareo al SU son sustanciales, y se estima que sobrepasan en estos momentos los 4.000 millones de dólares por año (aproximadamente un 4% de los costes totales del SU ). El incremento de los costes con el paso del tiempo parece reflejar el crecimiento de la prevalencia de las visitas al SU por mareo y el aumento de porcentajes de utilización de la neuroimagen. Futuros estudios económicos deberían centrarse en el desglose de los costes totales, y hacer énfasis en las áreas de alto uso y coste que pueden ser reducidas sin riesgo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99059/1/acem12168.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99059/2/acem12168-sup-0001-DataSupplementS1.pd

The impact of varying time scales on the quality of cancer projections based on the Bayesian age-period-cohort model

Projection of age-specific cancer incidence and mortality data play an integral role in planning and research. A wide range of methods used for these projections has been developed and put into practice. Many statistical software packages, such as Nordpred and the iterative Lee-Carter package, for projecting age-specific cancer incidence and mortality data implicitly assume that data are aggregated to five-year intervals on the time-scale (periods). However, data aggregation may not always be appropriate and information may get lost. In the field of spatial statistics, care is taken in choosing an appropriate spatial scale to analyse the data of interest; how- ever, less care is taken in choosing an appropriate time-scale in temporal analyses. In this thesis, the effect of varying temporal scales on the precision and accuracy of projections for selected female cancer mortality data sets from the World Health Organisation Mortality Database is investigated. Three temporal scales have been explored; five-year data aggregation, five-year model-specific aggregation and yearly data structure with no aggregation. Projections are obtained based on these three scales using the BAPC R-package, an R-package which implements Bayesian age- period-cohort (APC) models, where smoothing is applied to each time scale. Also, the hyperpriors for the precision parameter of the smoothing effects are carefully cho- sen to make them transferable between the different time aggregation. The models are estimated using integrated nested Laplace approximations (INLA). Calibration and sharpness of the projections are jointly assessed based on the absolute error and the continuous ranked probability score. The study shows that annual to five-year data aggregation might not be ideal for projections since clues on yearly trends can not be monitored. However if any form of aggregation needs to be done, then model-specific aggregation might be useful, depending on the application

Chemical characterization and antioxidant potential of wild ganoderma species from Ghana

The chemical characterization and antioxidant potential of twelve wild strains of Ganoderma sp. from Ghana, nine (LS1-LS9) of which were found growing wild simultaneously on the same dying Delonix regia tree, were evaluated. Parameters evaluated included the nutritional value, composition in sugars, fatty acids, phenolic and other organic compounds and some vitamins and vitamin precursors. Antioxidant potential was evaluated by investigating reducing power, radical scavenging activity and lipid peroxidation inhibition using five in vitro assays. Protein, carbohydrate, fat, ash and energy contents ranged between 15.7-24.5 g/100 gdw, 73.31-81.90 g/100 g, 0.48-1.40 g/100 g, 0.68-2.12 g/100 g ash and 396.1-402.02 kcal/100 g, respectively. Fatty acids such as linoleic, oleic and palmitic acids were relatively abundant. Free sugars included rhamnose, fructose, mannitol, sucrose and trehalose. Total tocopherols, organic acids and phenolic compounds' content ranged between 741-3191 µg/100 g, 77-1003 mg/100 g and 7.6-489 µg/100 g, respectively. There were variations in the ß-glucans, ergosterol and vitamin D 2 contents. The three major minerals in decreasing order were K > P > S. Ganoderma sp. strain AM1 showed the highest antioxidant activity. This study reveals, for the first time, chemical characteristics of Ganoderma spp. which grew simultaneously on the same tree.The authors thank H.N.A. Wellington of University of Ghana for showing us the location of the LS1–9 samples and for aiding in the sample collection. The authors also thank the Foundation for Science and Technology (FCT, Lisbon, Portugal) and FEDER under Program PT2020 for financial support to CIMO (Pest-OE/AGR/UI0690/2015) and L. Barros (SFRH/BPD/107855/2015) grant. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020 and FCT. We also thank the Nutrient and Phytochemical Analytic Shared Resource, part of the OSU Comprehensive Cancer Center (NIH P30 CA016058), where ergosterol and vitamin D2 were analyzed, the OSU Food Innovation Center for financial support, and the OSU Center for Advanced Functional Foods Research and Entrepreneurship for in-kind support. Author Contributions: Mary Obodai designed the study and participated in the manuscript writing. Deborah L. Narh. Mensah and Nii Korley Kortei conducted bibliographic research, data organization and participated in the manuscript writing. Angela Fernandes, Lillian Barros and Isabel C. F. R. Ferreira performed all the chemical analysis, the statistics and participated in the manuscript writing. Deborah L. Narh Mensah, Matilda Dzomeku, Juanita Prempeh and Richard K. Takli collected all the samples. Matthew Teegarden and Steven J. Schwartz conducted analysis on bioactive compounds and edited manuscript. Mary Obodai, Deborah L. Narh. Mensah, Nii Korley Kortei and Isabel C.F.R. Ferreira revised the manuscript writing.info:eu-repo/semantics/publishedVersio

Meaningful Stimuli and the Enhancement of Equivalence Class Formation

After the direct training of baseline conditional relations, the emergence of derived relations that have the properties of reflexivity, symmetry and transitivity documents the formation of equivalence classes. Studies on the formation of these equivalence classes have shown that the probability of class formation is influenced by a wide array of variables. The meaningfulness of the stimuli used has been found to be one of such important variables. The formation of equivalence classes that include meaningless or abstract stimuli only has been found to be less probable. However, the inclusion of a meaningful stimulus, such as a familiar picture in a set of other meaningless stimuli can help to convert that set of stimuli into an equivalence class. In five studies with college students, this thesis has explored the properties of meaningful stimuli that account for the class enhancement they produce. Study 1 explored how a simple discriminative function acquired by an abstract stimulus through simultaneous and/or successive discrimination training enhanced the formation of an equivalence class of which that stimulus was a member. In two experiments, Study 2 investigated how the order of training, familiar pictures, and abstract stimuli that acquired discriminative functions influenced equivalence class formation. In yet another two experiments, Study 3 studied the effect of the use of a meaningful stimulus as a class member on equivalence class formation. Two parallel groups were trained to form three 3-node 5-member equivalence classes (A B C D E) under the simultaneous protocol in both experiments. The baseline relations AB, BC, CD, and DE were trained in a serialized manner in Experiment 1 while Experiment 2 involved the concurrent training of baseline relations. Study 4 investigated whether the acquisition of an identity conditional discriminative function by a meaningless stimulus using simultaneous or delayed matching procedures would influence the likelihood of formation of an equivalence class of which it is a member along with other meaningless stimuli. In a replication to Study 4, Study 5 investigated how equivalence class formation was enhanced by the inclusion of one abstract stimulus that had acquired an identity or arbitrary conditional discriminative function on a simultaneous or delayed basis, prior to the establishment of the classes. In addition to their traditional connotative and denotative properties, these studies extend our knowledge on the class enhancing properties of meaningful stimuli to include acquired discriminative functions and delayed relational (identity and arbitrary) functions. The studies also strengthen existing findings that the inclusion of a meaningful stimulus in a set of other meaningless class enhances the formation of equivalence classes. However, its inclusion alone is shown to be insufficient to generate the class enhancement and that, the order of introduction in the serial training of the baseline relations for a class, the structural location of the meaningful stimulus in the training structure as well as its behavioral functions interact with the meaningful stimulus to account for their class enhancement. Finally, there was a strong concordance between two trial formats: matching to sample trials during class formation and sorting during post class formation sorting test in terms of participants’ performances indicative of equivalence class formation.CC-BY-S

Emergency Department Time Course for Mild Traumatic Brain Injury Workup

Introduction: Mild traumatic brain injury (mTBI) is a common cause for visits to the emergency department (ED). The actual time required for an ED workup of a patient with mTBI in the United States is not well known. National emergency medicine organizations have recommended reducing unnecessary testing, including head computed tomography (CT) for these patients.10 Methods: To examine this issue, we developed a care map that included each step of evaluation of mTBI (Glasgow Coma Scale Score 13-15) – from initial presentation to the ED to discharge. Time spent at each step was estimated by a panel of United States emergency physicians and nurses. We subsequently validated time estimates using retrospectively collected, real-time data at two EDs. Length of stay (LOS) time differences between admission and discharged patients were calculated for patients being evaluated for mTBI. Results: Evaluation for mTBI was estimated at 401 minutes (6.6 hours) in EDs. Time related to head CT comprised about one-half of the total LOS. Real-time data from two sites corroborated the estimate of median time difference between ED admission and discharge, at 6.3 hours for mTBI. Conclusion: Limiting use of head CT as part of the workup of mTBI to more serious cases may reduce time spent in the ED and potentially improve overall ED throughput

The Effect of Different Fracturing Fluids on the Productivity of Multi-Staged Fractured Marcellus Shale Horizontal Wells

While hydraulic fracturing has undeniably improved the production from oil and gas reservoirs, this technology is not without limitations. The primary hurdles lie in the areas of proppant transport, fluid rheology, and stress management. Despite the extensive research conducted in this domain, there remains a considerable amount of work to be done for comprehensive solutions that account for the complex interactions among fracturing fluid, proppant distribution, and geomechanical conditions. Achieving this will then make room for a holistic and efficient hydraulic fracturing strategy. This study addresses the above-mentioned problem by examining the impact of fluid type on proppant transport and distribution leading to productivity improvement for a multi-staged fractured Marcellus Shale horizontal well. In addition, stress shadow impact and the extent to which various fracture properties contribute to production are evaluated. The findings can be used to enhance fracture treatment design in the Marcellus shale through optimum fluid selection and stage spacing to reduce the impact of the stress shadow. Available core plug measurements, well logs, and image logs were analyzed to determine the shale petrophysical and geomechanical properties, including natural fracture (fissure) distribution, to develop a horizontal Marcellus Shale well model. Available laboratory measurements and published data were analyzed to determine the gas adsorption characteristics and the shale compressibility. The impact of the shale compressibility as a function of net stress was then incorporated into the model by developing multipliers for fissure and matrix permeability as well as the hydraulic fracture conductivity. The hydraulic fracture properties estimated using the GOHFER 3D software were incorporated into the developed reservoir model and ultimately, the impact of fluid type and stress shadow on proppant transport and the gas production were investigated. The reservoir model’s credibility was confirmed by a close match between the actual and predicted production. The fracture heights induced by all the fluids remained within the pay zone and the entire fracture height contributed to the production. High Viscosity Friction Reducer (HVFR) resulted in relatively larger fracture volume (with increased fracture height) in comparison to Slickwater, Crosslinked Gel, and Hybrid fluids thus resulting in improved productivity. The cross-linked gel also improved productivity but was found to be inferior to HVFR. High Percentage Reduction indicated the adverse impact of stress shadow on hydraulic fracture properties and gas production. The impact of the stress shadow on the production is, however, more pronounced during early production due to higher production rates