3,780 research outputs found

    Microfluidic Device Architecture for Electrochemical Patterning and Detection of Multiple DNA Sequences

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    Electrochemical biosensors pose an attractive solution for point-of-care diagnostics because they require minimal instrumentation and they are scalable and readily integrated with microelectronics. The integration of electrochemical biosensors with microscale devices has, however, proven to be challenging due to significant incompatibilities among biomolecular stability, operation conditions of electrochemical sensors, and microfabrication techniques. Toward a solution to this problem, we have demonstrated here an electrochemical array architecture that supports the following processes in situ, within a self-enclosed microfluidic device: (a) electrode cleaning and preparation, (b) electrochemical addressing, patterning, and immobilization of sensing biomolecules at selected sensor pixels, (c) sequence-specific electrochemical detection from multiple pixels, and (d) regeneration of the sensing pixels. The architecture we have developed is general, and it should be applicable to a wide range of biosensing schemes that utilize gold–thiol self-assembled monolayer chemistry. As a proof-of-principle, we demonstrate the detection and differentiation of polymerase chain reaction (PCR) amplicons diagnostic of human (H1N1) and avian (H5N1) influenza

    Prevalence of pelvic floor disorders in women with suspected gynecological malignancy: a survey-based study

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    Understanding of pelvic floor disorders among women with gynecological cancer is limited. The objective of this study was to describe the prevalence of pelvic floor disorders in women with suspected gynecological malignancy before surgery

    Microfluidic Device Architecture for Electrochemical Patterning and Detection of Multiple DNA Sequences

    Get PDF
    Electrochemical biosensors pose an attractive solution for point-of-care diagnostics because they require minimal instrumentation and they are scalable and readily integrated with microelectronics. The integration of electrochemical biosensors with microscale devices has, however, proven to be challenging due to significant incompatibilities among biomolecular stability, operation conditions of electrochemical sensors, and microfabrication techniques. Toward a solution to this problem, we have demonstrated here an electrochemical array architecture that supports the following processes in situ, within a self-enclosed microfluidic device: (a) electrode cleaning and preparation, (b) electrochemical addressing, patterning, and immobilization of sensing biomolecules at selected sensor pixels, (c) sequence-specific electrochemical detection from multiple pixels, and (d) regeneration of the sensing pixels. The architecture we have developed is general, and it should be applicable to a wide range of biosensing schemes that utilize gold–thiol self-assembled monolayer chemistry. As a proof-of-principle, we demonstrate the detection and differentiation of polymerase chain reaction (PCR) amplicons diagnostic of human (H1N1) and avian (H5N1) influenza

    Lower Extremity Peripheral Artery Disease and Quality of Life Among Older Individuals in the Community

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    BACKGROUND: Evidence regarding the association of lower extremity peripheral arterial disease with quality of life (QOL) is mainly from selected clinical populations or relatively small clinical cohorts. Thus, we investigated this association in community-derived populations. METHODS AND RESULTS: Using data of 5115 participants aged 66 to 90 years from visit 5 (2011-2013) of the Atherosclerosis Risk in Communities Study, we quantified the associations of ankle-brachial index (ABI) with several QOL parameters, including 12-item Short-Form Health Survey (SF-12), after accounting for potential confounders using linear and logistic regression models. Peripheral arterial disease defined by an ABI <0.90 (n=402), was independently associated with a low SF-12 Physical Component Summary score (-3.26 [95% CI -5.60 to -0.92]), compared to the ABI reference 1.10 to 1.19 (n=1900) but not with the Mental Component Summary score (-0.07 [-2.21 to 2.06]). A low ABI was significantly associated with poorer status of all SF-12 physical domains (physical functioning, role-physical, bodily pain, and general health) but only vitality out of 4 mental domains. Similarly, low ABI values were more consistently associated with other physically related QOL parameters (leisure-time exercise/activity/walking) than mentally related parameters (significant depressive symptoms and hopeless feeling). Lower physical QOL was observed even in individuals with borderline low ABI (0.90 to 0.99; n=426). CONCLUSIONS: Low ABI (even borderline) was independently associated with poor QOL, especially for physical components, in community-dwelling older adults. QOL is a critical element for older adults, and thus, further studies are warranted to assess whether peripheral arterial disease-specific management can improve QOL in older populations

    Cost-Effectiveness of Laparoscopic Hysterectomy With Morcellation Compared With Abdominal Hysterectomy for Presumed Myomas

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    Hysterectomy for presumed leiomyomata is one of the most common surgical procedures performed in non-pregnant women in the United States. Laparoscopic hysterectomy (LH) with morcellation is an appealing alternative to abdominal hysterectomy (AH), but may result in dissemination of malignant cells and worse outcomes in the setting of an occult leiomyosarcoma. We sought to evaluate the cost-effectiveness of LH versus AH

    Brane Decay of a (4+n)-Dimensional Rotating Black Hole. III: spin-1/2 particles

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    In this work, we have continued the study of the Hawking radiation on the brane from a higher-dimensional rotating black hole by investigating the emission of fermionic modes. A comprehensive analysis is performed that leads to the particle, power and angular momentum emission rates, and sheds light on their dependence on fundamental parameters of the theory, such as the spacetime dimension and angular momentum of the black hole. In addition, the angular distribution of the emitted modes, in terms of the number of particles and energy, is thoroughly studied. Our results are valid for arbitrary values of the energy of the emitted particles, dimension of spacetime and angular momentum of the black hole, and complement previous results on the emission of brane-localised scalars and gauge bosons.Comment: Latex file, JHEP style, 34 pages, 16 figures Energy range in plots increased, minor changes, version published in JHE

    Multiple plant traits shape the genetic basis of herbivore community assembly

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    1. Community genetics research has posited a genetic basis to the assembly of ecological communities. For arthropod herbivores in particular, there is strong support that genetic variation in host plants is a key factor shaping their diversity and composition. However, the specific plant phenotypes underlying herbivore responses remain poorly explored for most systems. 2. We address this knowledge gap by examining the influence of both genetic and phenotypic variation in a dominant host-plant species, Salix hookeriana, on its associated arthropod herbivore community in a common garden experiment. Specifically, we surveyed herbivore responses among five different arthropod feeding guilds to 26 distinct S. hookeriana genotypes. Moreover, we quantified the heritability of a suite of plant traits that determine leaf quality (e.g. phenolic compounds, trichomes, specific leaf area, C : N) and whole-plant architecture, to identify which traits best accounted for herbivore community responses to S. hookeriana genotype. 3. We found that total herbivore abundance and community composition differed considerably among S. hookeriana genotypes, with strong and independent responses of several species and feeding guilds driving these patterns. We also found that leaf phenolic chemistry displayed extensive heritable variation, whereas leaf physiology and plant architecture tended to be less heritable. Of these traits, herbivore responses were primarily associated with leaf phenolics and plant architecture; however, different herbivore species and feeding guilds were associated with different sets of traits. Despite our thorough trait survey, plant genotype remained a significant predictor of herbivore responses in most trait association analyses, suggesting that unmeasured host-plant characteristics and/or interspecific interactions were also contributing factors. 4. Taken together, our results support that the genetic basis of herbivore community assembly occurs through a suite of plant traits for different herbivore species and feeding guilds. Still, identifying these phenotypic mechanisms requires measuring a broad range of plant traits and likely further consideration of how these traits affect interspecific interactions.Fil: Barbour, Matthew A.. University Of British Columbia; CanadáFil: Rodriguez Cabal, Mariano Alberto. University Of British Columbia; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Wu, Elizabeth T.. Humboldt State University; Estados UnidosFil: Julkunen Tiitto, Riitta. University of Eastern Finland; FinlandiaFil: Ritland, Carol E.. University Of British Columbia; CanadáFil: Miscampbell, Allyson E.. University Of British Columbia; CanadáFil: Jules, Erik S.. Humboldt State University; Estados UnidosFil: Crutsinger, Gregory M.. University Of British Columbia; Canad

    College Students as Facilitators in Reducing Adolescent Obesity Disparity in Southern Appalachia: Team up for Healthy Living

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    The proportion of obese adolescents in Southern Appalachia is among the highest in the nation. Through funding from the National Institute on Minority Health and Health Disparities — National Institutes of Health, the Team Up for Healthy Living project was a cluster-randomized trial targeting obesity prevention in adolescents through a cross-peer intervention. The specific aims of the project were to: 1) develop a peer-based health education program focusing on establishing positive peer norms towards healthy eating and physical activity (PA) among high school students, 2) test program efficacy, and 3) explore mechanisms underlying the program. The study was guided by the Theory of Planned Behavior, which presupposes that human behavior is primarily driven by attitude, subjective norms, perceived behavioral control, and social support. To deliver the intervention, undergraduate students from the disciplines of public health, nutrition, and kinesiology were hired as peer facilitators. Ten area high schools were invited to participate, were matched on demographics and then randomized to intervention or control. The primary outcomes of the study included body mass status, dietary behaviors, PA, and sedentary behaviors which were assessed at baseline and at three and twelve months post baseline. Intervention schools received Team Up for Healthy Living curriculum, which consists of eight 40-minute sessions. The curriculum focused on improving nutrition awareness, PA, leadership and communication. Control schools received their regularly scheduled Lifetime Wellness curriculum. The long-term goal of the study was to establish an effective academia–community partnership program to address adolescent obesity disparity in Southern Appalachia

    Untangling the Relationship Between Antiretroviral Therapy Use and Incident Pregnancy: A Marginal Structural Model Analysis Using Data From 47,313 HIV-Positive Women in East Africa

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    BACKGROUND: Scale-up of triple-drug antiretroviral therapy (ART) in Africa has transformed the context of childbearing for HIV-positive women and may impact pregnancy incidence in HIV programs. METHODS: Using observational data from 47,313 HIV-positive women enrolled at 26 HIV clinics in Kenya and Uganda between 2001 and 2009, we calculated the crude cumulative incidence of pregnancy for the pre-ART and on-ART periods. The causal effect of ART use on incident pregnancy was assessed using inverse probability weighted marginal structural models, and the relationship was further explored in multivariable Cox models. RESULTS: Crude cumulative pregnancy incidence at 1 year after enrollment/ART initiation was 4.0% and 3.9% during the pre-ART and on-ART periods, respectively. In marginal structural models, ART use was not significantly associated with incident pregnancy [hazard ratio = 1.06; 95% confidence interval (CI): 0.99 to 1.12]. Similarly, in Cox models, there was no significant relationship between ART use and incident pregnancy (cause-specific hazard ratio: 0.98; 95% CI: 0.91 to 1.05), but effect modification was observed. Specifically, women who were pregnant at enrollment and on ART had an increased risk of incident pregnancy compared to those not pregnant at enrollment and not on ART (cause-specific hazard ratio: 1.11; 95% CI: 1.01 to 1.23). CONCLUSIONS: In this large cohort, ART initiation was not associated with incident pregnancy in the general population of women enrolling in HIV care but rather only among those pregnant at enrollment. This finding further highlights the importance of scaling up access to lifelong treatment for pregnant women
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