507 research outputs found

    Extension and approximation of mm-subharmonic functions

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    Let ΩCn\Omega\subset \mathbb C^n be a bounded domain, and let ff be a real-valued function defined on the whole topological boundary Ω\partial \Omega. The aim of this paper is to find a characterization of the functions ff which can be extended to the inside to a mm-subharmonic function under suitable assumptions on Ω\Omega. We shall do so by using a function algebraic approach with focus on mm-subharmonic functions defined on compact sets. We end this note with some remarks on approximation of mm-subharmonic functions

    Influence of 5-fluorouracil-loaded microsphere formulation on efficient rat glioma radiosensitization

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    PURPOSE: To determine (i) the efficiency of radiosensitizing 5-FU-loaded microspheres and (ii) the impact of microparticle formulation on response to treatment. METHODS: C6 tumor-bearing rats were stereotactically implanted with microspheres and/or allocated to: control groups (untreated) or treatment (only radiotherapy; fast-release 5-FU microspheres + radiotherapy; slow-release 5-FU microspheres + radiotherapy). The next day, fractionated radiotherapy, limited to the hemibrain, was initiated in all treated animals. The irradiation cycle included 36 Gy, given in 9 sessions for 3 consecutive weeks. Tumor development was assessed by T2-weighted MRI. RESULTS: 5-FU microspheres associated with radiotherapy caused a 47% complete remission rate (9/19) as opposed to the 8% rate (1/12) when radiotherapy alone or 0% in control animals. Drug delivery for 3 weeks produced better survival results (57%) compared to one-week sustained release (41%). MR images showed exponentially increasing tumor volumes during the first half of the radiotherapy cycle, followed by a decrease, and the disappearance of the tumor if survival exceeded 120 days. CONCLUSIONS: 5-FU controlled delivery is a promising strategy for radiosensitizing gliomas. Drug delivery system formulation is unambiguously implicated in both the response to treatment and the limitation of toxic side effects

    Validity of the Polar V800 heart rate monitor to measure RR intervals at rest

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    Purpose To assess the validity of RR intervals and short-term heart rate variability (HRV) data obtained from the Polar V800 heart rate monitor, in comparison to an electrocardiograph (ECG). Method Twenty participants completed an active orthostatic test using the V800 and ECG. An improved method for the identification and correction of RR intervals was employed prior to HRV analysis. Agreement of the data was assessed using intra-class correlation coefficients (ICC), Bland–Altman limits of agreement (LoA), and effect size (ES). Results A small number of errors were detected between ECG and Polar RR signal, with a combined error rate of 0.086 %. The RR intervals from ECG to V800 were significantly different, but with small ES for both supine corrected and standing corrected data (ES 0.999 for both supine and standing corrected intervals. When analysed with the same HRV software no significant differences were observed in any HRV parameters, for either supine or standing; the data displayed small bias and tight LoA, strong ICC (>0.99) and small ES (≤0.029). Conclusions The V800 improves over previous Polar models, with narrower LoA, stronger ICC and smaller ES for both the RR intervals and HRV parameters. The findings support the validity of the Polar V800 and its ability to produce RR interval recordings consistent with an ECG. In addition, HRV parameters derived from these recordings are also highly comparable

    Emission spectra and intrinsic optical bistability in a two-level medium

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    Scattering of resonant radiation in a dense two-level medium is studied theoretically with account for local field effects and renormalization of the resonance frequency. Intrinsic optical bistability is viewed as switching between different spectral patterns of fluorescent light controlled by the incident field strength. Response spectra are calculated analytically for the entire hysteresis loop of atomic excitation. The equations to describe the non-linear interaction of an atomic ensemble with light are derived from the Bogolubov-Born-Green-Kirkwood-Yvon hierarchy for reduced single particle density matrices of atoms and quantized field modes and their correlation operators. The spectral power of scattered light with separated coherent and incoherent constituents is obtained straightforwardly within the hierarchy. The formula obtained for emission spectra can be used to distinguish between possible mechanisms suggested to produce intrinsic bistability.Comment: 18 pages, 5 figure

    An overview of early investigational drugs for the treatment of human papilloma virus infection and associated dysplasia

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    Introduction: High-risk HPV (HR-HPV) related invasive cervical cancer (ICC) causes >270,000 deaths per annum world-wide with over 85% of these occurring in low-resource countries. Ablative and excisional treatment modalities are restricted for use with high-grade pre-cancerous cervical disease with HPV infection and low-grade dysplasia mostly managed by a watch-and-wait policy.Areas Covered: Various pharmacological approaches have been investigated as non-destructive alternatives for the treatment of HR-HPV infection and associated dysplasia. These are discussed dealing with efficacy, ease-of-use (physician or self-applied), systemic or locally applied, side-effects, cost and risks. The main focus is the perceived impact on current clinical practice of a self-applied, effective and safe pharmacological anti-HPV treatment.Expert opinion: Current prophylactic HPV vaccines are expensive, HPV type restricted and have little effect in already infected women. Therapeutic vaccines are under development but are also HPV type-restricted. At present, the developed nations use national cytology screening and surgical procedures to treat only women identified with HPV-related high-grade dysplastic disease. However, since HPV testing is rapidly replacing cytology as the test-of-choice, a suitable topically-applied and low-cost antiviral treatment could be an ideal solution for treatment of HPV infection per se with test-of-cure carried out by repeat HPV testing. Cytology would only then be necessary for women who remained HPV positive. Although of significant benefit in the developed countries, combining such a treatment with self-sampled HPV testing could revolutionise the management of this disease in the developing world which lack both the infrastructure and resources to establish national cytology screening programs

    Optical Drug Monitoring: Photoacoustic Imaging of Nanosensors to Monitor Therapeutic Lithium in Vivo

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    Personalized medicine could revolutionize how primary care physicians treat chronic disease and how researchers study fundamental biological questions. To realize this goal, we need to develop more robust, modular tools and imaging approaches for in vivo monitoring of analytes. In this report, we demonstrate that synthetic nanosensors can measure physiologic parameters with photoacoustic contrast, and we apply that platform to continuously track lithium levels in vivo. Photoacoustic imaging achieves imaging depths that are unattainable with fluorescence or multiphoton microscopy. We validated the photoacoustic results that illustrate the superior imaging depth and quality of photoacoustic imaging with optical measurements. This powerful combination of techniques will unlock the ability to measure analyte changes in deep tissue and will open up photoacoustic imaging as a diagnostic tool for continuous physiological tracking of a wide range of analytes

    Partial regularity and t-analytic sets for Banach function algebras

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    In this note we introduce the notion of t-analytic sets. Using this concept, we construct a class of closed prime ideals in Banach function algebras and discuss some problems related to Alling’s conjecture in H infinity. A description of all closed t-analytic sets for the disk-algebra is given. Moreover, we show that some of the assertions in [8] concerning the O-analyticity and S-regularity of certain Banach function algebras are not correct. We also determine the largest set on which a Douglas algebra is pointwise regular

    Intoxications par les pesticides

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    Single-crystalline, wormlike hematite photoanodes for efficient solar water splitting

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    A hematite photoanode showing a stable, record-breaking performance of 4.32 mA/cm(2) photoelectrochemical water oxidation current at 1.23 V vs. RHE under simulated 1-sun (100 mW/cm(2)) irradiation is reported. This photocurrent corresponds to ca. 34% of the maximum theoretical limit expected for hematite with a band gap of 2.1 V. The photoanode produced stoichiometric hydrogen and oxygen gases in amounts close to the expected values from the photocurrent. The hematitle has a unique single-crystalline "wormlike" morphology produced by in-situ two-step annealing at 550 degrees C and 800 degrees C of beta-FeOOH nanorods grown directly on a transparent conducting oxide glass via an all-solution method. In addition, it is modified by platinum doping to improve the charge transfer characteristics of hematite and an oxygen-evolving co-catalyst on the surface.open2
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