2,911 research outputs found

    Computer program for compressible flow network analysis

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    Program solves problem of an arbitrarily connected one dimensional compressible flow network with pumping in the channels and momentum balancing at flow junctions. Program includes pressure drop calculations for impingement flow and flow through pin fin arrangements, as currently found in many air cooled turbine bucket and vane cooling configurations

    Density of States Extracted from Modified Recursion Relations

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    We evaluate the density of states (DOS) associated with tridiagonal symmetric Hamiltonian matrices and study the effect of perturbation on one of its entries. Analysis is carried out by studying the resulting three-term recursion relation and the corresponding orthogonal polynomials of the first and second kind. We found closed form expressions for the new DOS in terms of the original one when perturbation affects a single diagonal or off-diagonal site or a combination of both. The projected DOS is also calculated numerically and its relation to the average DOS is explored both analytically and numerically.Comment: 15 pages including 8 figures (one in color

    Efficacy of hepatic transplantation in patients with primary sclerosing cholangitis

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    Controlled trials to assess the therapeutic benefit of orthotopic hepatic transplantation (OHTx) for primary sclerosing cholangitis (PSC) cannot be justified in view of improvement of patient survival after this operation since 1981. However, the actual patient survival with OHTx can be compared with the Mayo model estimated survival probabilities without OHTx. This model, which encompasses physical, biochemical and histopathologic parameters of PSC, was constructed from a study of 392 conservatively treated PSC patients at five international centers in England and North America. We compared the actual survival of 216 adult patients with the diagnosis of advanced PSC who underwent hepatic replacement with the expected survival estimated by the Mayo PSC natural history model, 'the simulated control technique.' OHTx was performed at the University of Pittsburgh and Mayo Medical Center between 5 December 1981 and 26 December 1990. The mean (plus or minus standard deviation) post-OHTx follow-up period was 34 ± 25 months (range of zero to 104 months). Before transplantation, biliary or portal hypertensive operation, or both, was performed upon 104 patients. At operation, the mean age of recipients was 42.1 ± 11.3 years and the mean value of total serum bilirubin was 13.3 ± 13.0 milligrams per deciliter. Extensive septal fibrosis and cirrhosis were histologically documented in 97 percent of the patients, with splenomegaly in 63 percent. Immunosuppressive therapy was based primarily on cyclosporin in 184 recipients and FK-506 in 32. Within six months, the Kaplan-Meier survival probability after OHTx (0.89) already was higher than predicted by the Mayo model (0.83). At five years, the Kaplan-Meier actual survival with OHTx was 0.73 compared with 0.28 expected Mayo model survival. The overall increased survival rate with transplantation was statistically significant (chi-square equals 126.6; p<0.001). At all risk stratifications, OHTx significantly improved survival with a p value of 0.031 (low risk), 0.001 (moderate risk) and <0.001 (high risk). Thus, OHTx is effective therapy for PSC. Disease gravity and unsuspected cholangiocarcinoma in the excised native liver adversely influenced short and long term survival rates after transplantation, respectively

    Cancer phase I trial design using drug combinations when a fraction of dose limiting toxicities is attributable to one or more agents

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    Drug combination trials are increasingly common nowadays in clinical research. However, very few methods have been developed to consider toxicity attributions in the dose escalation process. We are motivated by a trial in which the clinician is able to identify certain toxicities that can be attributed to one of the agents. We present a Bayesian adaptive design in which toxicity attributions are modeled via Copula regression and the maximum tolerated dose (MTD) curve is estimated as a function of model parameters. The dose escalation algorithm uses cohorts of two patients, following the continual reassessment method (CRM) scheme, where at each stage of the trial, we search for the dose of one agent given the current dose of the other agent. The performance of the design is studied by evaluating its operating characteristics when the underlying model is either correctly specified or misspecified. We show that this method can be extended to accommodate discrete dose combinations

    Impact of genotype 1 and 2 of porcine reproductive and respiratory syndrome viruses on interferon-α responses by plasmacytoid dendritic cells

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    Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) infections are characterized by prolonged viremia and viral shedding consistent with incomplete immunity. Type I interferons (IFN) are essential for mounting efficient antiviral innate and adaptive immune responses, but in a recent study, North American PRRSV genotype 2 isolates did not induce, or even strongly inhibited, IFN-α in plasmacytoid dendritic cells (pDC), representing "professional IFN-α-producing cells". Since inhibition of IFN-α expression might initiate PRRSV pathogenesis, we further characterized PRRSV effects and host modifying factors on IFN-α responses of pDC. Surprisingly, a variety of type 1 and type 2 PRRSV directly stimulated IFN-α secretion by pDC. The effect did not require live virus and was mediated through the TLR7 pathway. Furthermore, both IFN-γ and IL-4 significantly enhanced the pDC production of IFN-α in response to PRRSV exposure. PRRSV inhibition of IFN-α responses from enriched pDC stimulated by CpG oligodeoxynucleotides was weak or absent. VR-2332, the prototype genotype 2 PRRSV, only suppressed the responses by 34%, and the highest level of suppression (51%) was induced by a Chinese highly pathogenic PRRSV isolate. Taken together, these findings demonstrate that pDC respond to PRRSV and suggest that suppressive activities on pDC, if any, are moderate and strain-dependent. Thus, pDC may be a source of systemic IFN-α responses reported in PRRSV-infected animals, further contributing to the puzzling immunopathogenesis of PRRS

    Content analysis of public opinion on sexual expression and dementia: Implications for nursing home policy development

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    Citation: Syme, M. L., Yelland, E., Cornelison, L., Poey, J. L., Krajicek, R., & Doll, G. (2016). Content analysis of public opinion on sexual expression and dementia: Implications for nursing home policy development. Health Expectations. doi:10.1111/hex.12509Purpose: We examined public opinion of sexual expression and dementia to inform nursing home policy and practice. Design and Methods: A content analysis was conducted on public comments (N=1194) posted in response to a New York Times article about a highly publicized legal case involving a husband engaging in sexual acts with his wife who had dementia, living in a nursing home. Researchers utilized constant comparative analysis to code the comments; reliability analysis showed moderately strong agreement at the subcategory level. Data were also coded to indicate whether the commenter thought the couple should or should not have been allowed to be sexual. Results: One primary theme was identified: conditions necessary for someone to be sexual. Six categories were identified within this theme, with the public commentary considering factors such as marital relationships, intimacy needs and several sexual consent-related issues as key conditions necessary to be sexual in a nursing home setting. Overall, the majority of commenters were in support of sexual expression for an individual with dementia in the described situation. Discussion: This study revealed sexual expression among individuals with dementia is a contentious issue with strong public opinions about how this should be managed in a nursing home setting. These opinions should be considered as policy related to sexual expression in nursing homes is developed. © 2016 John Wiley & Sons Ltd

    Texts From My Parents

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    Remember that horrible feeling you got in the pit of your stomach when you first saw that Facebook friend request from your mom? How about when your dad, who had previously criticized you for your incessant, “senseless” text messaging, started texting you about his bowel movements? All of a sudden, two worlds are beginning to merge: your family life and your social life. And as hard as you try to resist the inexplicable force pulling these worlds together, in the end you’ll probably be fruitless. Mom’s request might remain untouched in the corner of your Facebook page for a while, but eventually somehow she’ll guilt you into accepting (she did, after all, bring you into this world)
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