530 research outputs found

    Promoting Economic Mobility by Increasing Postsecondary Education

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    Explores policy options for expanding educational opportunities for low-income students to enhance upward economic mobility. Examines the effectiveness of student aid in promoting college completion and proposes a plan for better guidance and preparation

    Evaluation of Ovarian Cysts

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    Initial evaluation of an ovarian cyst is largely determined by its characteristics on ultrasonography, in addition to the presence of symptoms, laboratory evaluation, and patient history. Women with an ovarian cyst, but with no symptoms, family or personal history of cancer (e.g., ovarian, breast, colorectal), physical or laboratory evidence suggestive of infection, pregnancy, or systemic illness, are considered at low risk of ovarian cancer and may be followed with serial ultrasonography. (Strength of Recommendation [SOR]: B, based on a prospective cohort study.) A cyst identified on transvaginal ultrasonography is usually benign if it is thin-walled, unilocular, smooth-bordered, and less than 10 cm in diameter. Cyst aspiration and treatment with combined oral contraceptives do not hasten cyst resolution. (SOR: A, based on good-quality randomized controlled trials.) A complex cyst without benign features should be aggressively evaluated for ovarian cancer. (SOR: C, based on expert opinion.

    Expanding Economic Opportunity for Young Men and Boys of Color through Employment and Training

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    Young men of color have long experienced lower earnings and higher unemployment compared to young white men. Many factors have contributed to these negative outcomes: persistent discrimination, hiring practices of employers, geographic and social isolation, substandard secondary education, lack of career and postsecondary educational guidance, inadequate career and technical education, and higher incarceration rates. This paper focuses on promising strategies for improving the labor market outcomes of low-income young men of color. It outlines an employment-focused approach to improving economic opportunities and outcomes for these young men, highlighting potential policy, system and institutional reforms as well as program investments

    Glass fracture surface energy calculated from crystal structure and bond-energy data

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    We present a novel method to predict the fracture surface energy of oxide glasses, {\gamma}, using readily available crystallographic structure data of their isochemical crystal and tabled diatomic chemical bond energies, D0. The method assumes that {\gamma} equals the fracture surface energy of the most likely cleavage plane of the crystal. Calculated values were in excellent agreement with those calculated from measured glass density and D0 in an earlier work. This finding demonstrates a remarkable equivalence between crystal cleavage planes and glass fracture surfaces

    Rapid induction of therapeutic hypothermia using convective-immersion surface cooling: Safety, efficacy and outcomes

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    Therapeutic hypothermia has become an accepted part of post-resuscitation care. Efforts to shorten the time from return of spontaneous circulation to target temperature have led to the exploration of different cooling techniques. Convective-immersion uses a continuous shower of 2 °C water to rapidly induce hypothermia. The primary purpose of this multi-center trial was to evaluate the feasibility and speed of convective-immersion cooling in the clinical environment. The secondary goal was to examine the impact of rapid hypothermia induction on patient outcome. 24 post-cardiac arrest patients from 3 centers were enrolled in the study; 22 agreed to participate until the 6-month evaluations were completed. The median rate of cooling was 3.0 °C/h. Cooling times were shorter than reported in previous studies. The median time to cool the patients to target temperature (\u3c34 °C) was 37 min (range 14–81 min); and only 27 min in a subset of patients sedated with propofol. Survival was excellent, with 68% surviving to 6 months; 87% of survivors were living independently at 6 months. Conductive-immersion surface cooling using the ThermoSuit® System is a rapid, effective method of inducing therapeutic hypothermia. Although the study was not designed to demonstrate impact on outcomes, survival and neurologic function were superior to those previously reported, suggesting comparative studies should be undertaken. Shortening the delay from return of spontaneous circulation to hypothermic target temperature may significantly improve survival and neurologic outcome and warrants further study

    Rapid Detection of Botulinum Neurotoxins—A Review

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    A toxin is a poisonous substance produced within living cells or organisms. One of the most potent groups of toxins currently known are the Botulinum Neurotoxins (BoNTs). These are so deadly that as little as 62 ng could kill an average human; to put this into context that is approximately 200,000 × less than the weight of a grain of sand. The extreme toxicity of BoNTs leads to the need for methods of determining their concentration at very low levels of sensitivity. Currently the mouse bioassay is the most widely used detection method monitoring the activity of the toxin; however, this assay is not only lengthy, it also has both cost and ethical issues due to the use of live animals. This review focuses on detection methods both existing and emerging that remove the need for the use of animals and will look at three areas; speed of detection, sensitivity of detection and finally cost. The assays will have wide reaching interest, ranging from the pharmaceutical/clinical industry for production quality management or as a point of care sensor in suspected cases of botulism, the food industry as a quality control measure, to the military, detecting BoNT that has been potentially used as a bio warfare agent

    3D microstructure effects in Ni-YSZ anodes : prediction of effective transport properties and optimization of redox stability

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    This study investigates the influence of microstructure on the effective ionic and electrical conductivities of Ni-YSZ (yttria-stabilized zirconia) anodes. Fine, medium, and coarse microstructures are exposed to redox cycling at 950 ºC. FIB (focused ion beam)-tomography and image analysis are used to quantify the effective (connected) volume fraction (Φeff), constriction factor (β), and tortuosity (τ). The effective conductivity (σeff) is described as the product of intrinsic conductivity (σ0) and the so-called microstructure-factor (M): σeff = σ0 x M. Two different methods are used to evaluate the M-factor: (1) by prediction using a recently established relationship, Mpred = ε β^0.36/τ^5.17, and (2) by numerical simulation that provides conductivity, from which the simulated M-factor can be deduced (Msim). Both methods give complementary and consistent information about the effective transport properties and the redox degradation mechanism. The initial microstructure has a strong influence on effective conductivities and their degradation. Finer anodes have higher initial conductivities but undergo more intensive Ni coarsening. Coarser anodes have a more stable Ni phase but exhibit lower YSZ stability due to lower sintering activity. Consequently, in order to improve redox stability, it is proposed to use mixtures of fine and coarse powders in different proportions for functional anode and current collector layers

    3D microstructure effects in Ni-YSZ anodes : influence of TPB lengths on the electrochemical performance

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    3D microstructure-performance relationships in Ni-YSZ anodes for electrolyte-supported cells are investigated in terms of the correlation between the triple phase boundary (TPB) length and polarization resistance (Rpol). Three different Ni-YSZ anodes of varying microstructure are subjected to eight reduction-oxidation (redox) cycles at 950 °C. In general the TPB lengths correlate with anode performance. However, the quantitative results also show that there is no simplistic relationship between TPB and Rpol. The degradation mechanism strongly depends on the initial microstructure. Finer microstructures exhibit lower degradation rates of TPB and Rpol. In fine microstructures, TPB loss is found to be due to Ni coarsening, while in coarse microstructures reduction of active TPB results mainly from loss of YSZ percolation. The latter is attributed to weak bottlenecks associated with lower sintering activity of the coarse YSZ. The coarse anode suffers from complete loss of YSZ connectivity and associated drop of TPBactive by 93%. Surprisingly, this severe microstructure degradation did not lead to electrochemical failure. Mechanistic scenarios are discussed for different anode microstructures. These scenarios are based on a model for coupled charge transfer and transport, which allows using TPB and effective properties as input. The mechanistic scenarios describe the microstructure influence on current distributions, which explains the observed complex relationship between TPB lengths and anode performances. The observed loss of YSZ percolation in the coarse anode is not detrimental because the electrochemical activity is concentrated in a narrow active layer. The anode performance can be predicted reliably if the volume-averaged properties (TPBactive, effective ionic conductivity) are corrected for the so-called short-range effect, which is particularly important in cases with a narrow active layer

    Plasminogen Activator Inhibitor-1 Promotes Neutrophil Infiltration and Tissue Injury on Ischemia–Reperfusion

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    Objective Ischemia-reperfusion (I/R) injury significantly contributes to organ dysfunction and failure after myocardial infarction, stroke, and transplantation. In addition to its established role in the fibrinolytic system, plasminogen activator inhibitor-1 has recently been implicated in the pathogenesis of I/R injury. The underlying mechanisms remain largely obscure. Approach and Results Using different in vivo microscopy techniques as well as ex vivo analyses and in vitro assays, we identified that plasminogen activator inhibitor-1 rapidly accumulates on microvascular endothelial cells on I/R enabling this protease inhibitor to exhibit previously unrecognized functional properties by inducing an increase in the affinity of 2 integrins in intravascularly rolling neutrophils. These events are mediated through low-density lipoprotein receptor-related protein-1 and mitogen-activated protein kinase-dependent signaling pathways that initiate intravascular adherence of these immune cells to the microvascular endothelium. Subsequent to this process, extravasating neutrophils disrupt endothelial junctions and promote the postischemic microvascular leakage. Conversely, deficiency of plasminogen activator inhibitor-1 effectively reversed leukocyte infiltration, microvascular dysfunction, and tissue injury on experimental I/R without exhibiting side effects on microvascular hemostasis. Conclusions Our experimental data provide novel insights into the nonfibrinolytic properties of the fibrinolytic system and emphasize plasminogen activator inhibitor-1 as a promising target for the prevention and treatment of I/R injury
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