823 research outputs found

    Comorbid Medical Conditions as Predictors of Overall Survival in Glioblastoma Patients

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    Glioblastoma (GBM) is an aggressive central nervous system tumor with a poor prognosis. This study was conducted to determine any comorbid medical conditions that are associated with survival in GBM. Data were collected from medical records of all patients who presented to VCU Medical Center with GBM between January 2005 and February 2015. Patients who underwent surgery/biopsy were considered for inclusion. Cox proportional hazards regression modeling was performed to assess the relationship between survival and sex, race, and comorbid medical conditions. 163 patients met inclusion criteria. Comorbidities associated with survival on individual-characteristic analysis included: history of asthma (Hazard Ratio [HR]: 2.63; 95% Confidence Interval [CI]: 1.24–5.58; p = 0.01), hypercholesterolemia (HR: 1.95; 95% CI: 1.09–3.50; p = 0.02), and incontinence (HR: 2.29; 95% CI: 0.95–5.57; p = 0.07). History of asthma (HR: 2.22; 95% CI: 1.02–4.83; p = 0.04) and hypercholesterolemia (HR: 1.99; 95% CI: 1.11–3.56; p = 0.02) were associated with shorter survival on multivariable analysis. Surgical patients with GBM who had a prior history of asthma or hypercholesterolemia had significantly higher relative risk for mortality on individual-characteristic and multivariable analyses

    Porous and Complex Flow Structures in Modern Technologies

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    Porous and Complex Flow Structures in Modern Technologies represents a new approach to the field, considering the fundamentals of porous media in terms of the key roles played by these materials in modern technology. Intended as a text for advanced undergraduates and as a reference for practicing engineers, the book uses the physics of flows in porous materials to tie together a wide variety of important issues from such fields as biomedical engineering, energy conversion, civil engineering, electronics, chemical engineering, and environmental engineering. Thus, for example, flows of water and oil through porous ground play a central role in energy exploration and recovery (oil wells, geothermal fluids), energy conversion (effluents from refineries and power plants), and environmental engineering (leachates from waste repositories). Similarly, the demands of miniaturization in electronics and in biomedical applications are driving research into the flow of heat and fluids through small-scale porous media (heat exchangers, filters, gas exchangers). Filters, catalytic converters, the drying of stored grains, and a myriad of other applications involve flows through porous media. By providing a unified theoretical framework that includes not only the traditional homogeneous and isotropic media but also models in which the assumptions of representative elemental volumes or global thermal equilibrium fail, the book provides practicing engineers the tools they need to analyze complex situations that arise in practice. This volume includes examples, solved problems and an extensive glossary of symbols

    Toward Continuous Monitoring of Breath Biochemistry: A Paper-Based Wearable Sensor for Real-Time Hydrogen Peroxide Measurement in Simulated Breath

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    Exhaled breath contains a large amount of biochemical and physiological information concerning one’s health and provides an alternative route to noninvasive medical diagnosis of diseases. In the case of lung diseases, hydrogen peroxide (H2O2) is an important biomarker associated with asthma, chronic obstructive pulmonary disease, and lung cancer and can be detected in exhaled breath. The current method of breath analysis involves condensation of exhaled breath, is not continuous or real time, and requires two separate and bulky devices, complicating the periodic or long-term monitoring of a patient. We report the first disposable paper-based electrochemical wearable sensor that can monitor exhaled H2O2 in artificial breath calibration-free and continuously, in real time, and can be integrated into a commercial respiratory mask for on-site testing of exhaled breath. To improve precision for sensing H2O2, we perform differential electrochemical measurement by amperometry in which screen-printed Prussian Blue-mediated and nonmediated carbon electrodes are used for differential analysis. We were able to measure H2O2 in simulated breath in a concentration-dependent manner in real time, confirming its functionality. This proposed system is versatile, and by modifying the chemistry of the sensing electrodes, our method of differential sensing can be extended to continuous monitoring of other analytes in exhaled breath

    HT2008-56446 FORMULATION OF FILM THEORY EQUATIONS FOR MODELING OF CONDENSATION OF STEAM-AIR MIXTURES IN A SHELL AND TUBE CONDENSER

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    ABSTRACT Through development of the fundamental equations of Film Theory, condensation of steam in the presence of air in a horizontal counter-current shell and one-path tube condenser is modeled. The interaction between heat and mass transfer and hydrodynamics in the shell-side is taken into consideration. A comparison between the predictions of the model and a set of experimental data available in the archival literature indicates excellent accuracy of the new formulation. The accuracy of the method is further validated by generating profiles of the temperature and pressure drops of the gas flow through the baffles, at various air leakages. Additionally, the effects of air leakage and upstream cooling water temperature are investigated to determine how they influence the total condensation rate, shell-side gas temperature and pressure drops. The results show that the total condensation rate decreases 5% and 20.5% for an air leakage of 1% and 5%, respectively, compared to the situation of pure vapor. Also, increasing the inlet cooling water temperature from 46

    Acupuncture Point Localization Varies Among Acupuncturists

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    Background: Studies assessing the point-specific effect of acupuncture or the characteristics of acupuncture points (APs) tend to yield inconclusive results. In order to identify a possible confounding factor, we aimed to examine the variability in AP localization by means of a survey. Material and Methods: Attendees of the 14th ICMART (International Council of Medical Acupuncture and Related Techniques) congress as well as DAGfA (German Medical Society of Acupuncture) lecturers and students were asked to locate and mark the APs LI 10 and TH 5 on a research assistant's arm. Identified points were transferred into a coordinate system, and the respective bivariate distribution function was calculated. Additionally, participants filled out a questionnaire about their acupuncture education and experience, the acupuncture style and point localization techniques used most frequently, and their estimation of the size of an AP. Results: The areas of the ellipses, theoretically containing 95% of AP localizations, varied between 44.49 and 5.18 cm(2). The largest distance between 2 identified points was 8.45 cm for LI 10 and 5.3 cm for TH 5. Apart from being trained at the same school, no other factor could be identified that determined the variability in AP localization. Conclusion: Our results indicate that congruity of AP localization among experienced acupuncturists might be low. Although there are some limitations to our results, this possible bias should be taken into account when conducting acupuncture trials and interpreting results of previous acupuncture studies

    Autocatalytic metallization of fabrics using Si ink, for biosensors, batteries and energy harvesting

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    Commercially available metal inks are mainly designed for planar substrates (for example, polyethylene terephthalate foils or ceramics), and they contain hydrophobic polymer binders that fill the pores in fabrics when printed, thus resulting in hydrophobic electrodes. Here, a low‐cost binder‐free method for the metallization of woven and nonwoven fabrics is presented that preserves the 3D structure and hydrophilicity of the substrate. Metals such as Au, Ag, and Pt are grown autocatalytically, using metal salts, inside the fibrous network of fabrics at room temperature in a two‐step process, with a water‐based silicon particle ink acting as precursor. Using this method, (patterned) metallized fabrics are being enabled to be produced with low electrical resistance (less than 3.5 Ω sq−1). In addition to fabrics, the method is also compatible with other 3D hydrophilic substrates such as nitrocellulose membranes. The versatility of this method is demonstrated by producing coil antennas for wireless energy harvesting, Ag–Zn batteries for energy storage, electrochemical biosensors for the detection of DNA/proteins, and as a substrate for optical sensing by surface enhanced Raman spectroscopy. In the future, this method of metallization may pave the way for new classes of high‐performance devices using low‐cost fabrics

    A novel form of recessive limb girdle muscular dystrophy with mental retardation and abnormal expression of alpha-dystroglycan

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    Cataloged from PDF version of article.The limb girdle muscular dystrophies are a heterogeneous group of conditions characterized by proximal muscle weakness and disease onset ranging from infancy to adulthood. We report here eight patients from seven unrelated families affected by a novel and relatively mild form of autosomal recessive limb girdle muscular dystrophy (LGMD2) with onset in the first decade of life and characterized by severe mental retardation but normal brain imaging. Immunocytochemical studies revealed a significant selective reduction of α-dystroglycan expression in the muscle biopsies. Linkage analysis excluded known loci for both limb girdle muscular dystrophy and congenital muscular dystrophies in the consanguineous families. We consider that this represents a novel form of muscular dystrophy with associated brain involvement. The biochemical studies suggest that it may belong to the growing number of muscular dystrophies with abnormal expression of α-dystroglycan. © 2003 Published by Elsevier B.V

    Analysis of Various Polarization Asymmetries In The Inclusive bs+b\to s \ell^+ \ell^- Decay In The Fourth-Generation Standard Model

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    In this study a systematical analysis of various polarization asymmetries in inclusive b \rar s \ell^+ \ell^- decay in the standard model (SM) with four generation of quarks is carried out. We found that the various asymmetries are sensitive to the new mixing and quark masses for both of the μ\mu and τ\tau channels. Sizeable deviations from the SM values are obtained. Hence, b \rar s \ell^+ \ell^- decay is a valuable tool for searching physics beyond the SM, especially in the indirect searches for the fourth-generation of quarks (t,b)t', b').Comment: 19 Pages, 10 Figures, 3 Table

    On embodied memetic evolution and the emergence of behavioural traditions in Robots

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    This paper describes ideas and initial experiments in embodied imitation using e-puck robots, developed as part of a project whose aim is to demonstrate the emergence of artificial culture in collective robot systems. Imitated behaviours (memes) will undergo variation because of the noise and heterogeneities of the robots and their sensors. Robots can select which memes to enact, and-because we have a multi-robot collective-memes are able to undergo multiple cycles of imitation, with inherited characteristics. We thus have the three evolutionary operators: variation, selection and inheritance, and-as we describe in this paper-experimental trials show that we are able to demonstrate embodied movement-meme evolution. © 2011 Springer-Verlag
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