49 research outputs found

    On Dynamical Models for Radio Galaxies

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    The tailed radio galaxies that have been called ``Type I'' are not a uniform set. To study their dynamics, we have used the Ledlow-Owen data set, which provides a new sample of 250 radio galaxies in nearby Abell clusters. These sources divide into two clear categories based on their radio morphology. Type A sources (``straight'') contain nearly straight jets which are embedded in outer radio lobe. Type B sources (``tailed'') have a well-collimated jet flow which undergoes a sudden transition, at an inner hot spot, to a less collimated flow which continues on and forms a radio tail. We have not found any separation of these classes in terms of radio power, radio flux size, galaxy power or external gas density. We propose the difference is due to the development, or not, of a disruptive flow instability, such as Kelvin-Helmholtz, and the saturation of the instability when it develops.Comment: 10 pages, 4 figures, to appear in 'Life Cycles of Radio Galaxies', ed. J. Biretta etal, New Astronomy Review

    Lack of Association between Polymorphism in ABCC2 Gene and Response to Antiepileptic Drug Treatment in Croatian Patients with Epilepsy

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    Despite advances in antiepileptic drug (AED) therapy, about one-third of patients with epilepsy are resistant to drug treatment. Functional impact of polymorphisms in drug-efflux transporter genes may contribute to multidrug resistance theory. Studies on ABCB1 gene gave contradictory results and available data suggest that this polymorphism may not directly cause altered P-glycoprotein (Pgp) transport activity but may be associated with one or more causal variants in the stretch of linkage disequilibrium or is caused by multiple gene polymorphisms. Genetic polymorphisms also occur frequently in other transmembrane transport systems including the multidrug resistance proteins (MRPs, ABCC2). The aim of this research was to investigate the possible association of ABCC2 gene polymorphisms G1249A in exon 10 and C24T in exon 1 with the development of drug resistance. This cross-sectional study is a part of ongoing pharmacogenomic study of epilepsy in Croatian population. All patients enrolled in the study had an established diagnosis of partial complex epilepsy with or without secondary generalization with non lesional brain MRI with epilepsy protocol and have been suffering for more than two years. They were divided into two groups. The first group comprised 52 patients refractory to the current therapy, while the second group consisted of 45 patients with well-controlled seizures. Our data did not identify any significant association between genetic polymorphisms of exon 1 (24C>T) and exon 10 (1249G<A) of ABCC2 gene or any combined effect in response to AED treatment and development of drug resistance in patients with partial complex epilepsy. Statistical significant difference was not found in genotype based analysis, allele frequency, haplotype and combined genotype analysis

    ARTIFICAL NEURAL NETWORKS IN RF MEMS SWITCH MODELING

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    The increased growth of the applications of RF MEMS switches in modern communication systems has created an increased need for their accurate and efficient models. Artificial neural networks have appeared as a fast and efficient modeling tool providing similar accuracy as the standard commercial simulation packages. This paper gives an overview of the applications of artificial neural networks in modeling of RF MEMS switches, in particular of the capacitive shunt switches, proposed by the authors of the paper. Models for the most important switch characteristics in electrical and mechanical domains are considered, as well as the inverse models aimed to determine the switch bridge dimensions for given requirements for the switch characteristics

    Effect of microencapsulated granulas contained in the natural extracts on postsurgical wound healing

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    BackgroundThe innovative complex technology of encapsulation of the natural extracts allows the products to be more efficient in surgical wound healing due to penetration of the microcapsules in the soft tissues.AimsThe aim of the randomized controlled trial was to evaluate the effectiveness of microencapsulated natural extracts contained in the gel on wound healing process after oral surgical procedures. Methods The study included 95 patients with indications for endodontic surgery: third molar surgical extraction or dental implants placement. The patients were randomly divided in two groups based on the postsurgical protocol on treating the wound after surgery: A/: Subgroup 1: GinGinat group used a gel composed of different natural products (GinGinat gel, LoB Foundation, Paris, France) for treating the surgical area; B/ Subgroup 2: Standard protocol used saline solution for treating the wound after surgery. At the seven day follow upallpatients were asked to rate their experience and satisfaction on the recovery process after surgery based on a questionnaire. They were observed and evaluated for satisfaction with the recovery process based on using Likert-type scale.Results The results showed a statistically significant difference in the postoperative recovery period between the GinGinat and standard group (p < 0.001) based on a therapist’s evaluation. The GinGinat group was rated with the higher clinical score compared to the standard group (p < 0.001). There was a statistically significant difference in the recovery postoperative period between the GinGinat and standard group as rated based on the results of a patient’s questionnaire (p < 0.001).ConclusionThe results showed clinical improvement and better postsurgical healing of the wounds as well as the stronger analgesic effect after the application of microencapsulated granulas which are contained in the natural extracts as opposed to the standard postsurgical protocol

    Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

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    BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P &lt; 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P &lt; 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

    Modeling longitudinal changes in maximal-intensity exercise performance in young male rowing athletes.

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    The purpose of the current study was to examine the effect of age and body size upon maximal-intensity exercise performance in young rowing athletes. Male participants (n = 171) aged 12-18 years were assessed using an "all-out" 30-s rowing ergometer test, and reassessed after 12 months. The highest rate of performance development, which amounts to [mean(SD)] +34%(23%) and +32%(23%) for mean and maximal power output, respectively, is observed between the ages of 12 and 13, while this rate of development gradually declines as the athletes mature through adolescence. Performance increases with body size, and mass, stature and chronological age all proved to be significant (all p < .05) explanatory variables of mean power output, with respective exponents [mean(SE)] of 0.56(0.08), 1.84(0.30) and 0.07(0.01), and of maximal power output, with respective exponents of 0.54(0.09), 1.76(0.32) and 0.06(0.01). These findings may help coaches better understand the progression of rowing performance during adolescence

    Experimental study of physical parameters significant in fullerene synthesis

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    In this work, the effect of physical parameters on the yield of fullerene, synthesized in a hollow cathode plasma reactor is investigated. The experimental investigations done previously have shown that the fullerene yield depended on tehcnical parameters - the current intensity, inert gas pressure, type of gas and interelectrode gap. The aim of this work was to show that the fullerene yield depends on physical parameters - carbon concentration, carbon flow rate from the interelectrode gap, axial temperature and temperature gradient between the. arc channel and the chamber walls as,well. It was found that fullerene synthesis occurs in an inert heat bath with dimensions determined by die temperature gradient. The lower temperature limit is around 2000 K and the value of the upper limit is die value of the axis temperature which depends on the discharge conditions. The synthesis of fullerenes is more effective if the carbon concentration in the heat bath is large and the carbon flow rate from that zone to colder parts of chamber is small

    Controlled Measurement Setup for Ultra-Wideband Dielectric Modeling of Muscle Tissue in 20–45 °C Temperature Range

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    In order to design electromagnetic applicators for diagnostic and therapeutic applications, an adequate dielectric tissue model is required. In addition, tissue temperature will heavily influence the dielectric properties and the dielectric model should, thus, be extended to incorporate this temperature dependence. Thus, this work has a dual purpose. Given the influence of temperature, dehydration, and probe-to-tissue contact pressure on dielectric measurements, this work will initially present the first setup to actively control and monitor the temperature of the sample, the dehydration rate of the investigated sample, and the applied probe-to-tissue contact pressure. Secondly, this work measured the dielectric properties of porcine muscle in the 0.5–40 GHz frequency range for temperatures from 20 °C to 45 °C. Following measurements, a single-pole Cole–Cole model is presented, in which the five Cole–Cole parameters (ϵ∞, σs, Δϵ, τ, and α) are given by a first order polynomial as function of tissue temperature. The dielectric model closely agrees with the limited dielectric models known in literature for muscle tissue at 37 °C, which makes it suited for the design of in vivo applicators. Furthermore, the dielectric data at 41–45 °C is of great importance for the design of hyperthermia applicators

    Controlled Measurement Setup for Ultra-Wideband Dielectric Modeling of Muscle Tissue in 20–45 °C Temperature Range

    No full text
    In order to design electromagnetic applicators for diagnostic and therapeutic applications, an adequate dielectric tissue model is required. In addition, tissue temperature will heavily influence the dielectric properties and the dielectric model should, thus, be extended to incorporate this temperature dependence. Thus, this work has a dual purpose. Given the influence of temperature, dehydration, and probe-to-tissue contact pressure on dielectric measurements, this work will initially present the first setup to actively control and monitor the temperature of the sample, the dehydration rate of the investigated sample, and the applied probe-to-tissue contact pressure. Secondly, this work measured the dielectric properties of porcine muscle in the 0.5–40 GHz frequency range for temperatures from 20 °C to 45 °C. Following measurements, a single-pole Cole–Cole model is presented, in which the five Cole–Cole parameters (ϵ∞, σs, Δϵ, τ, and α) are given by a first order polynomial as function of tissue temperature. The dielectric model closely agrees with the limited dielectric models known in literature for muscle tissue at 37 °C, which makes it suited for the design of in vivo applicators. Furthermore, the dielectric data at 41–45 °C is of great importance for the design of hyperthermia applicators

    Complementary Split-Ring Resonator with Improved Dielectric Spatial Resolution

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