74 research outputs found
An ambipolar BODIPY derivative for a white exciplex OLED and cholesteric liquid crystal laser toward multifunctional devices
A new interface engineering method is demonstrated for the preparation of an efficient white organic light-emitting diode (WOLED) by embedding an ultrathin layer of the novel ambipolar red emissive compound 4,4-difluoro-2,6-di(4-hexylthiopen-2-yl)-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (bThBODIPY) in the exciplex formation region. The compound shows a hole and electron mobility of 3.3 × 10–4 and 2 × 10–4 cm2 V–1 s–1, respectively, at electric fields higher than 5.3 × 105 V cm–1. The resulting WOLED exhibited a maximum luminance of 6579 cd m–2 with CIE 1931 color coordinates (0.39; 0.35). The bThBODIPY dye is also demonstrated to be an effective laser dye for a cholesteric liquid crystal (ChLC) laser. New construction of the ChLC laser, by which a flat capillary with an optically isotropic dye solution is sandwiched between two dye-free ChLC cells, provides photonic lasing at a wavelength well matched with that of a dye-doped planar ChLC cell
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Optimal tuned mass-damper-inerter (TMDI) design in wind-excited tall buildings for occupants’ comfort serviceability performance and energy harvesting
The tuned mass-damper-inerter (TMDI) couples the classical tuned mass-damper (TMD), with an inerter device developing a resisting force proportional to the relative acceleration of its ends by the “inertance” constant. Previous works demonstrated that the inclusion of the TMDI leads to more efficient broadband vibration control for a range of different structures under different actions. This paper proposes a novel optimal TMDI design formulation to address occupants’ comfort in wind-excited slender tall buildings susceptible to vortex shedding (VS) effects and to explore optimal TMDI’s potential for transforming part of the windinduced kinetic energy to usable electricity in tall buildings. Attention is focused on investigating benefits of TMDIs with different inertial properties (i.e., secondary mass/weight and inertance) configured in different topologies defined by the number of floors spanned by the inerter device to connect the secondary mass to the building structure. Optimally designed TMDIs for a wide range of inertial properties and three different topologies are obtained through numerical solution of the underlying optimization problem for a benchmark 305.9m tall building with more than 6 height-to-width ratio subjected to experimentally calibrated spatiallycorrelated across-wind force field accounting for VS effects. Performance-based design (PBD) graphs on the TMDI inertial (mass-inertance) plane are furnished demonstrating that any fixed structural performance level in terms of occupants’ comfort (i.e., peak top floor acceleration) can be achieved through lightweight TMDIs if compared with classical TMDs as long as sufficient inertance is provided. Further, TMDI robustness to host structure properties and to reference wind velocity is shown to increase by increasing inertance or by spanning more floors in connecting the secondary mass with the host structure by the inerter. Lastly, it is found that increased available energy for harvesting in wind excited tall buildings is achieved by incorporating electromagnetic motors in TMDIs with varying damping property, while concurrent reduced floor acceleration and increased available energy for harvesting is accomplished by TMDI topologies with inerters spanning more floors
Myocardial Structural Alteration and Systolic Dysfunction in Preclinical Hypertrophic Cardiomyopathy Mutation Carriers
BACKGROUND: To evaluate the presence of myocardial structural alterations and subtle myocardial dysfunction during familial screening in asymptomatic mutation carriers without hypertrophic cardiomyopathy (HCM) phenotype. METHODS AND FINDINGS: Sixteen HCM families with pathogenic mutation were studied and 46 patients with phenotype expression (Mut+/Phen+) and 47 patients without phenotype expression (Mut+/Phen-) were observed. Twenty-five control subjects, matched with the Mut+/Phen- group, were recruited for comparison. Echocardiography was performed to evaluate conventional parameters, myocardial structural alteration by calibrated integrated backscatter (cIBS) and global and segmental longitudinal strain by speckle tracking analysis. All 3 groups had similar left ventricular dimensions and ejection fraction. Basal anteroseptal cIBS was the highest in Mut+/Phen+ patients (-14.0+/-4.6 dB, p-19.0 dB basal anteroseptal cIBS or >-18.0% basal anteroseptal longitudinal strain had a sensitivity of 98% and a specificity of 72% in differentiating Mut+/Phen- group from controls. CONCLUSION: The use of cIBS and segmental longitudinal strain can differentiate HCM Mut+/Phen- patients from controls with important clinical implications for the family screening and follow-up of these patients.published_or_final_versio
Conservation of the endangered Hawaiian fern 'ihi'ihilauākea (Marsilea villosa) : a synthesis of experimental restoration, community ecology, and population genetics
Ph.D. University of Hawaii at Manoa 2012.Includes bibliographical references.Conservation of endangered plants is a critical step in maintaining and restoring global biodiversity. Management efforts such as in situ conservation and restoration through plant reintroduction are more likely to be successful if decisions are based on carefully designed scientific research. Marsilea villosa is an endangered, endemic Hawaiian fern with only seven remaining populations on the islands of O'ahu and Moloka'i restricted to ephemerally flooding dry lowlands. Among its uncommon traits are long-lived sporocarps (i.e., highly modified leaves with drought resistant walls containing sporangia and spores), a requirement of flood and drought to complete its sexual life cycle, and extensive vegetative growth. In this dissertation I conducted three studies to answer the following questions: 1) Which management techniques best facilitate growth of M. villosa in outplanting for reintroduction? 2) Which ecological factors affect the growth of M. villosa under field conditions?
3) How much genetic variation exists within and among M. villosa populations?
4) What are the implications of these studies for how M. villosa is managed?
I conducted a restoration experiment to evaluate the effects of light, flooding, weeding, and their interactions on the growth of M. villosa outplanted in a common-garden. I found that the combination of flooding and shade treatments promoted the greatest increase in M. villosa growth, and that the effects of this interaction grew stronger over time. After drought occurred, shade also increased M. villosa growth in the absence of weeding. In a three-year field study, I examined ecological factors that influenced M. villosa growth and confirmed that shade and flooding have positive synergistic effects, while the negative effects of associated non-native species differ with functional groups. In a population genetic study, the majority of genetic variation was found at the subpopulation level, but there was also genetic structure that showed strong differentiation among some populations and between the two islands. This research provides several explicit management recommendations that will increase the chances of success in conservation and restoration of Marsilea villosa, and a model upon which to base restoration of the more resilient endangered species in Hawaiʻi and worldwide
Final Section 409A regulations and their effect on offshore hedge fund deferral arrangements
Challenges of Improving the Evidence Base in Smaller Surgical Specialties, as Highlighted by a Systematic Review of Gastroschisis Management
<div><p>Objective</p><p>To identify methods of improving the evidence base in smaller surgical specialties, using a systematic review of gastroschisis management as an example.</p><p>Background</p><p>Operative primary fascial closure (OPFC), and silo placement with staged reduction and delayed closure (SR) are the most commonly used methods of gastroschisis closure. Relative merits of each are unclear.</p><p>Methods</p><p>A systematic review and meta-analysis was performed comparing outcomes following OPFC and SR in infants with simple gastroschisis. Primary outcomes of interest were mortality, length of hospitalization and time to full enteral feeding.</p><p>Results</p><p>751 unique articles were identified. Eight met the inclusion criteria. None were randomized controlled trials. 488 infants underwent OPFC and 316 underwent SR. Multiple studies were excluded because they included heterogeneous populations and mixed intervention groups. Length of stay was significantly longer in the SR group (mean difference 8.97 days, 95% CI 2.14–15.80 days), as was number of post-operative days to complete enteral feeding (mean difference 7.19 days, 95%CI 2.01–12.36 days). Mortality was not statistically significantly different, although the odds of death were raised in the SR group (OR 1.96, 95%CI 0.71–5.35).</p><p>Conclusions</p><p>Despite showing some benefit of OPFC over SR, our results are tempered by the low quality of the available studies, which were small and variably reported. Coordinating research through a National Paediatric Surgical Trials Unit could alleviate many of these problems. A similar national approach could be used in other smaller surgical specialties.</p></div
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Alzheimer Disease-associated Cortical Atrophy Does not Differ Between Chinese and Whites
PurposeTo assess whether there are differences in Alzheimer disease (AD)-associated atrophy regions in Chinese and white patients with AD versus cognitively normal older adults, and to test whether associations between clinical severity and gray matter volume are similar or different across these ethnic groups in a cross-sectional analysis.Materials and methodsChinese and white patients with AD, individuals with mild cognitive impairment, and cognitively normal controls (46 white and 48 Chinese) were clinically evaluated at an academic center within 1 year of magnetic resonance imaging acquisition. Clinical severity was assessed using the Clinical Dementia Rating Sum of Boxes and cortical atrophy was measured using voxel-based morphometry as well as Freesurfer. Chinese and white cohorts were demographically matched for age, sex, and education.ResultsClinical severity by diagnosis was similar across ethnicities. Chinese and white patient groups showed similar amounts of atrophy in the regions most affected in AD after accounting for demographic variables and head size. There was no significant difference between ethnic groups when compared by atrophy and clinical severity.ConclusionsOur study suggests that Chinese and white patients with AD, when matched demographically, are clinically and neuroanatomically similar on normalized measures of cortical atrophy and clinical severity
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