Esophageal temperature monitoring during radiofrequency catheter ablation: experimental study based on an agar phantom model

[EN] Although previous studies have established the feasibility of monitoring esophageal temperature during radiofrequency cardiac ablation using an esophageal temperature probe (ETP), some questions remain regarding its efficacy. The aims of this study were to study the effect of the location of the ETP on the temperature reached, and to test the characteristics of ETP as used in clinical practice. We constructed an agar phantom to model the thermal and electrical characteristics of the biological tissues (left atrium, esophagus and connective tissue). The ETP was positioned at 6.5 mm from an ablation electrode and at distances of 0, 5, 10, 15, 20 mm from the catheter axis. A thermocouple was located on the probe to measure the actual temperature of the external esophageal layer during the ablations (55 degrees C, 60 s). The mean temperatures reached at the thermocouple were significantly higher than those measured by the ETP (48.3 +/- 1.9 degrees C versus 39.6 +/- 1.1 degrees C). The temperature values measured with the ETP were significantly lower when the probe was located further from the catheter axis ( up to 2.5 degrees C lower when the distance from the probe - catheter axis was 2 cm). The dynamic calibration of the ETP showed a mean value for the time constant of 8 s. In conclusion, the temperature measured by the ETP always underestimates the temperature reached in the thermocouple. This fact can be explained by the distance gap between the thermocouple and probe and by the dynamic response of the ETP. The longer the distance between the ETP and catheter axis, the higher is the temperature difference.We would like to thank the R+D+i Linguistic Assistance Office at the Universidad Politécnica of Valencia for its help in revising this paper. This work was partially supported by the Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica del Ministerio de Educación y Ciencia of Spain (TEC 2005-04199/TCM) and by an R&D contract (CSIC-20060633) between Edwards Lifescience Ltd. and the Spanish Council for Scientific Research (CSIC).Rodriguez, I.; Lequerica, JL.; Berjano, E.; Herrero, M.; Hornero, F. (2007). Esophageal temperature monitoring during radiofrequency catheter ablation: experimental study based on an agar phantom model. Physiological Measurement. 28(5):453-463. https://doi.org/10.1088/0967-3334/28/5/001S453463285Berjano, E. J., & Hornero, F. (2005). What affects esophageal injury during radiofrequency ablation of the left atrium? An engineering study based on finite-element analysis. Physiological Measurement, 26(5), 837-848. doi:10.1088/0967-3334/26/5/020Hong Cao, Vorperian, V. R., Jang-Zem Tsai, Tungjitkusolmun, S., Eung Je Woo, & Webster, J. G. (2000). 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ALMA polarimetry measures magnetically aligned dust grains in the torus of NGC 1068

The obscuring structure surrounding active galactic nuclei (AGN) can be explained as a dust and gas flow cycle that fundamentally connects the AGN with their host galaxies. This structure is believed to be associated with dusty winds driven by radiation pressure. However, the role of magnetic fields, which are invoked in almost all models for accretion onto a supermassive black hole and outflows, is not thoroughly studied. Here we report the first detection of polarized thermal emission by means of magnetically aligned dust grains in the dusty torus of NGC 1068 using ALMA Cycle 4 polarimetric dust continuum observations ($0.07"$, $4.2$ pc; 348.5 GHz, $860$ $\mu$m). The polarized torus has an asymmetric variation across the equatorial axis with a peak polarization of $3.7\pm0.5$\% and position angle of $109\pm2^{\circ}$ (B-vector) at $\sim8$ pc east from the core. We compute synthetic polarimetric observations of magnetically aligned dust grains assuming a toroidal magnetic field and homogeneous grain alignment. We conclude that the measured 860 $\mu$m continuum polarization arises from magnetically aligned dust grains in an optically thin region of the torus. The asymmetric polarization across the equatorial axis of the torus arises from 1) an inhomogeneous optical depth, and 2) a variation of the velocity dispersion, i.e. variation of the magnetic field turbulence at sub-pc scales, from the eastern to the western region of the torus. These observations and modeling constrain the torus properties beyond spectral energy distribution results. This study strongly supports that magnetic fields up to a few pc contribute to the accretion flow onto the active nuclei.Comment: 19 pages, 11 figures (Accepted for Publication to ApJ

Aplicación de bioensayos a la evaluación ecotoxicológica de efluentes de tambo

Las aguas residuales de tambo son consideradas mezclas complejas integradas, principalmente, por sustancias excretadas por los animales y productos de limpieza. El objetivo de este trabajo fue evaluar la toxicidad de efluentes producidos durante el lavado en un tambo ovino. Para esto se aplicaron bioensayos con dos especies: Daphnia magna e Hydra plagiodesmica y se testearon muestras de efluente crudo y aireado. Los resultados mostraron una importante sensibilidad de ambas especies, sin embargo las especies no responden de igual manera ante las muestras. El efluente crudo presentó siempre niveles altos de toxicidad y la toxicidad disminuyó significativamente luego de airear las muestras lo que indica una significativa presencia de tóxicos oxidables y/o volátiles.Fil: Poggio Herrero, Ingrid Violeta. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Area de Toxicología; Argentina. Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Quimica; ArgentinaFil: Mariame, M. P.. Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Quimica; ArgentinaFil: Rodriguez, C.. Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Quimica; ArgentinaFil: Fanelli, Silvia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Limnología "dr. Raul A. Ringuelet". Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Instituto de Limnología ; Argentina. Universidad Nacional de La Pampa; ArgentinaFil: Porta, A.. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; ArgentinaFil: Fort, M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional la Pampa-San Luis. Estación Experimental Agropecuaria Anguil; ArgentinaFil: Mastrantonio Garrido, Guido Enrique. Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Quimica; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Area de Toxicología; Argentin

Using a causal smoothing to improve the performance of an on-line neural network glucose prediction algorithm

This work evaluates a spline-based smoothing method applied to the output of a glucose predictor. Methods:Our on-line prediction algorithm is based on a neural network model (NNM). We trained/validated the NNM with a prediction horizon of 30 minutes using 39/54 profiles of patients monitored with the Guardian® Real-Time continuous glucose monitoring system The NNM output is smoothed by fitting a causal cubic spline. The assessment parameters are the error (RMSE), mean delay (MD) and the high-frequency noise (HFCrms). The HFCrms is the root-mean-square values of the high-frequency components isolated with a zero-delay non-causal filter. HFCrms is 2.90±1.37 (mg/dl) for the original profiles

On the difference of torus geometry between hidden and non-hidden broad line active galactic nuclei

We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGN) with clumpy torus models. We compiled high spatial resolution ($\sim 0.3$--$0.7$ arcsec) mid-IR $N$-band spectroscopy, $Q$-band imaging and nuclear near- and mid-IR photometry from the literature. Combining these nuclear near- and mid-IR observations, far-IR photometry and clumpy torus models, enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties; type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without any published HBLR signature (NHBLR). Comparing the torus model parameters gives us the first quantitative torus geometrical view for each subgroup. We find that NHBLR AGN have smaller torus opening angles and larger covering factors than those of HBLR AGN. This suggests that the chance to observe scattered (polarized) flux from the BLR in NHBLR could be reduced by the dual effects of (a) less scattering medium due to the reduced scattering volume given the small torus opening angle and (b) the increased torus obscuration between the observer and the scattering region. These effects give a reasonable explanation for the lack of observed HBLR in some type-2 AGN.Comment: 13 pages, 5 figures, accepted for publication in Ap

Artificial pancreas using a personalized rule-based controller achieves overnight normoglycemia in patients with type 1 diabetes

Objective: This study assessed the efficacy of a closed-loop (CL) system consisting of a predictive rule-based algorithm (pRBA) on achieving nocturnal and postprandial normoglycemia in patients with type 1 diabetes mellitus (T1DM). The algorithm is personalized for each patient’s data using two different strategies to control nocturnal and postprandial periods. Research Design and Methods: We performed a randomized crossover clinical study in which 10 T1DM patients treated with continuous subcutaneous insulin infusion (CSII) spent two nonconsecutive nights in the research facility: one with their usual CSII pattern (open-loop [OL]) and one controlled by the pRBA (CL). The CL period lasted from 10 p.m. to 10 a.m., including overnight control, and control of breakfast. Venous samples for blood glucose (BG) measurement were collected every 20 min. Results: Time spent in normoglycemia (BG, 3.9–8.0 mmol/L) during the nocturnal period (12 a.m.–8 a.m.), expressed as median (interquartile range), increased from 66.6% (8.3–75%) with OL to 95.8% (73–100%) using the CL algorithm (P<0.05). Median time in hypoglycemia (BG, <3.9 mmol/L) was reduced from 4.2% (0–21%) in the OL night to 0.0% (0.0–0.0%) in the CL night (P<0.05). Nine hypoglycemic events (<3.9 mmol/L) were recorded with OL compared with one using CL. The postprandial glycemic excursion was not lower when the CL system was used in comparison with conventional preprandial bolus: time in target (3.9–10.0 mmol/L) 58.3% (29.1–87.5%) versus 50.0% (50–100%). Conclusions: A highly precise personalized pRBA obtains nocturnal normoglycemia, without significant hypoglycemia, in T1DM patients. There appears to be no clear benefit of CL over prandial bolus on the postprandial glycemi

Origin of the coloured karst fills in the neogene extensional system of ne iberia (Spain)

Karst fills from the onshore Penedès Basin and offshore València Trough display red, pink, orange and ochre colours. Their Mössbauer spectra indicate that Fe3+ contained in goethite is the dominant species in reddish-pink fills, whereas Fe2+ contained in dolomite and clays is more dominant in the orange and ochre ones. The lower δ 13C values and higher 87Sr/86Sr ratios of the karst fills with respect to their host carbonates can reflect the input of soil-derived CO2 and an external radiogenic source into the karst system. This geochemical composition, together with the non-carbonate fraction of the fills, consists of authigenic and transported illite, illite-smectite interlayers, as well as kaolinite, chlorite, pyrite, quartz, ilmenite, magnetite, apatite and feldspar, account for a mixed residual-detrital origin of fills. This polygenic origin agrees with that of the terra rossa sediments described worldwide. The different colours of karst fills are attributed to fluctuations in the water table, which control the Eh/pH conditions in the karst system. Thus, reddish colours reflect low water table levels and oxidising episodes, and orange and ochre ones reflect high water table levels and more reducing episodes. The greenish colours of fills could be related to fluctuations in the Fe3+/Fe2+ ratio