855 research outputs found
870 micron continuum observations of the bubble-shaped nebula Gum 31
We are presenting here a study of the cold dust in the infrared ring nebula
Gum 31. We aim at deriving the physical properties of the molecular gas and
dust associated with the nebula, and investigating its correlation with the
star formation in the region, that was probably triggered by the expansion of
the ionization front. We use 870 micron data obtained with LABOCA to map the
dust emission. The obtained LABOCA image was compared to archival IR,radio
continuum, and optical images. The 870 micron emission follows the 8 micron
(Spitzer), 250 micron, and 500 micron (Herschel) emission distributions showing
the classical morphology of a spherical shell. We use the 870 micron and 250
micron images to identify 60 dust clumps in the collected layers of molecular
gas using the Gaussclumps algorithm. The clumps have effective deconvolved
radii between 0.16 pc and 1.35 pc, masses between 70 Mo and 2800 Mo, and volume
densities between 1.1x10^3 cm^-3 and 2.04x10^5 cm^-3. The total mass of the
clumps is 37600 Mo. The dust temperature of the clumps is in the range from 21
K to 32 K, while inside the HII region reaches ~ 40 K. The clump mass
distribution is well-fitted by a power law dN/dlog(M/Mo) proportional to
M^(-alpha), with alpha=0.93+/-0.28. The slope differs from those obtained for
the stellar IMF in the solar neighborhood, suggesting that the clumps are not
direct progenitors of single stars/protostars. The mass-radius relationship for
the 41 clumps detected in the 870 microns emission shows that only 37% of them
lie in or above the high-mass star formation threshold, most of them having
candidate YSOs projected inside. A comparison of the dynamical age of the HII
region with the fragmentation time, allowed us to conclude that the collect and
collapse mechanism may be important for the star formation at the edge of Gum
31, although other processes may also be acting.Comment: 15 pages, 10 figures. Accepted for publication in A&
Determining water use of sorghum from two-source energy balance and radiometric temperatures
Estimates of surface actual evapotranspiration (ET) can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (<i>Sorghum bicolor</i>) field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB) model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h<sup>−1</sup> and ±1.0 mm d<sup>−1</sup> were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management
Molecular gas and star formation towards the IR dust bubble S24 and its environs
We present a multi-wavelength analysis of the infrared dust bubble S24, and
its environs, with the aim of investigating the characteristics of the
molecular gas and the interstellar dust linked to them, and analyzing the
evolutionary status of the young stellar objects (YSOs) identified there. Using
APEX data, we mapped the molecular emission in the CO(2-1), CO(2-1),
CO(2-1), and CO(3-2) lines in a region of about 5'x 5' in size
around the bubble. The cold dust distribution was analyzed using ATLASGAL and
Herschel images. Complementary IR and radio data were also used.The molecular
gas linked to the S24 bubble, G341.220-0.213, and G341.217-0.237 has velocities
between -48.0 km sec and -40.0 km sec. The gas distribution
reveals a shell-like molecular structure of 0.8 pc in radius bordering
the bubble. A cold dust counterpart of the shell is detected in the LABOCA and
Herschel images.The presence of extended emission at 24 m and radio
continuum emission inside the bubble indicates that the bubble is a compact HII
region. Part of the molecular gas bordering S24 coincides with the extended
infrared dust cloud SDC341.194-0.221. A cold molecular clump is present at the
interface between S24 and G341.217-0.237. As regards G341.220-0.213, the
presence of an arc-like molecular structure at the northern and eastern
sections of this IR source indicates that G341.220-0.213 is interacting with
the molecular gas. Several YSO candidates are found to be linked to the IR
extended sources, thus confirming their nature as active star-forming regions.
The total gas mass in the region and the H ambient density amount to 10300
M and 5900 cm, indicating that G341.220-0.213, G341.217-0.237,
and the S24 HII region are evolving in a high density medium. A triggering star
formation scenario is also investigated.Comment: 17 pages, 16 figures. Submitted to A&A. Revised according to the
referee repor
Comparación de las escalas APACHE II y BISAP en el pronóstico de pancreatitis aguda en un hospital del Perú: Comparison of the APACHE II and BISAP scales in the prognosis of acute pancreatitis in a hospital of Peru
Introduction: Acute pancreatitis continue to be a disease with significant morbidity and mortality. It is diagnosed by clinical criteria and the inflammatory process can lead to organ failure. The objective of the present study was to compare the scales of APACHE II and BISAP in the development of organic failure in acute pancreatitis from a public hospital of Perú. Pacients and methods: An analytical from validation of a diagnostic test. There were clinical records of patients who were hospitalized with the diagnosis of acute pancreatitis in the Internal Medicine service and the Intensive Care Unit were evaluated. The APACHE II and BISAP scales were applied and the ROC curve, the sensitivity, the specificity, the positive and negative predictive value was calculated for each one. SPSSv23 was used for statistical analysis. Results: Were reviewed 146 stories that met the inclusion criteria. An area under the curve of 0.957 was obtained for BISAP and 0.996 for APACHE II; with a sensitivity and specificity for APACHE II of 83% and 99%, for BISAP of 66% and 99%. In addition, the positive and negative predictive value for APACHE II is 83% and 99% , for BISAP 80% and 98% . Conclusion: The APACHE II scale was superior for detecting organ failure. It was determined that both scales have high specificity, however the APACHE II scale presented a higher sensitivity than the BISAP scale.Introducción: La pancreatitis aguda continúa siendo una enfermedad con morbilidad y mortalidad significativas. Se diagnostica mediante criterios clínicos y el proceso inflamatorio puede llegar hasta una falla de órganos. El objetivo del presente estudio fue comparar las escalas de APACHE II y BISAP en el desarrollo de falla orgánica en pacientes con pancreatitis aguda de un hospital público del Perú. Pacientes y métodos: Se realizó un estudio de validación de prueba diagnóstica. Se evaluaron las historias clínicas de pacientes que estuvieron hospitalizados con el diagnostico de pancreatitis aguda en el servicio de Medicina Interna y la Unidad de Cuidados Intensivos. Se aplicó las escalas APACHE II y BISAP, se calculó la curva ROC, sensibilidad, especificidad, valor predictivo positivo y negativo. Para el análisis estadístico se utilizó el SPSSv23. Resultados: Se evaluaron 146 historias de pacientes que cumplían con los criterios de inclusión. Se obtuvo un área bajo la curva de 0.957 para BISAP y 0.996 para APACHE II; con una sensibilidad y especificidad para APACHE II de 83% y 99%, para BISAP de 66% y 99%. El valor predictivo positivo y negativo para APACHE II es 83% and 99% y para BISAP 80% y 98%. Conclusiones: La escala de APACHE II fue superior para detectar falla de órganos. Se determinó que ambas escalas poseen alta especificidad, siendo mayor la sensibilidad en la escala BISAP
Liquid-liquid core-shell configurable mesoscale spherical acoustic lens with subwavelength focusing
El copyright pertenece a JSAP.[EN] In this work, we present a lens based on a thin hollow ABS spherical container structure, which can be filled up with different compatible liquids. The acoustic jet can be dynamically shaped by either shifting the operating frequency or modifying the geometry of the lens. We show for the first time that a spherical Ethanol ABS core¿shell acoustical lens immersed in water with low diameter-to-wavelength ratio equal to 6.67 and refraction index of 1.24 achieves a focusing spot narrower than 0.85¿. Experimental measurements validate simulation results and demonstrate the viability of these configurable spherical lenses in underwater acoustic focusing applications.This work has been supported by Spanish MINECO
TEC2015-70939-R and MICINN RTI2018-100792-B-I00 projects. S.P.-L. acknowledges
financial support from Universitat Politècnica de València grant
program PAID-01-18. I.V.M. and O.V.M. acknowledge the Tomsk Polytechnic
University Competitiveness Enhancement Program.Pérez-López, S.; Candelas Valiente, P.; Fuster Escuder, JM.; Rubio Michavila, C.; Minin, OV.; Minin, IV. (2019). Liquid-liquid core-shell configurable mesoscale spherical acoustic lens with subwavelength focusing. Applied Physics Express. 12(8):087001-1-087001-5. https://doi.org/10.7567/1882-0786/ab2c7aS087001-1087001-5128Meng, Q., Zhang, X., Cheng, L., Cao, P., Li, Y., Zhang, H., & Wang, G. (2011). Deep subwavelength focusing of light by a trumpet hyperlens. Journal of Optics, 13(7), 075102. doi:10.1088/2040-8978/13/7/075102Papaioannou, M., Plum, E., Rogers, E. T., & Zheludev, N. I. (2017). All-optical dynamic focusing of light via coherent absorption in a plasmonic metasurface. Light: Science & Applications, 7(3), 17157-17157. doi:10.1038/lsa.2017.157Hristov, H. D., & Rodriguez, J. M. (2012). Design Equation for Multidielectric Fresnel Zone Plate Lens. IEEE Microwave and Wireless Components Letters, 22(11), 574-576. doi:10.1109/lmwc.2012.2224099Ding, T., Yi, J., Li, H., Zhang, H., & Burokur, S. N. (2017). 3D field-shaping lens using all-dielectric gradient refractive index materials. Scientific Reports, 7(1). doi:10.1038/s41598-017-00681-zJiménez, N., Romero-García, V., Picó, R., Garcia-Raffi, L. M., & Staliunas, K. (2015). Nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating embedded in water. Applied Physics Letters, 107(20), 204103. doi:10.1063/1.4935917Hooke, R., Allestry, J., & Martyn, J. (1665). Micrographia, or, Some physiological descriptions of minute bodies made by magnifying glasses : with observations and inquiries thereupon /. doi:10.5962/bhl.title.105738Thomas, D. C., Gee, K. L., & Turley, R. S. (2009). A balloon lens: Acoustic scattering from a penetrable sphere. American Journal of Physics, 77(3), 197-203. doi:10.1119/1.3041420Knollman, G. C., Bellin, J. L. S., & Weaver, J. L. (1971). Variable‐Focus Liquid‐Filled Hydroacoustic Lens. The Journal of the Acoustical Society of America, 49(1B), 253-261. doi:10.1121/1.1912324Hasheminejad, S. M., & Azarpeyvand, M. (2004). Sound radiation from a liquid-filled underwater spherical acoustic lens with an internal eccentric baffled spherical piston. Ocean Engineering, 31(8-9), 1129-1146. doi:10.1016/j.oceaneng.2003.10.010Liu, T., Chen, F., Liang, S., Gao, H., & Zhu, J. (2019). Subwavelength Sound Focusing and Imaging Via Gradient Metasurface-Enabled Spoof Surface Acoustic Wave Modulation. Physical Review Applied, 11(3). doi:10.1103/physrevapplied.11.034061Ma, F., Chen, J., & Wu, J. H. (2019). Three-dimensional acoustic sub-diffraction focusing by coiled metamaterials with strong absorption. Journal of Materials Chemistry C, 7(17), 5131-5138. doi:10.1039/c9tc01243eRugar, D. (1984). Resolution beyond the diffraction limit in the acoustic microscope: A nonlinear effect. Journal of Applied Physics, 56(5), 1338-1346. doi:10.1063/1.334124De Rosny, J., & Fink, M. (2002). Overcoming the Diffraction Limit in Wave Physics Using a Time-Reversal Mirror and a Novel Acoustic Sink. Physical Review Letters, 89(12). doi:10.1103/physrevlett.89.124301Sarvazyan, A., Fillinger, L., & Gavrilov, L. R. (2010). Time-reversal acoustic focusing system as a virtual random phased array. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 57(4), 812-817. doi:10.1109/tuffc.2010.1486Heifetz, A., Kong, S.-C., Sahakian, A. V., Taflove, A., & Backman, V. (2009). Photonic Nanojets. Journal of Computational and Theoretical Nanoscience, 6(9), 1979-1992. doi:10.1166/jctn.2009.1254Luk’yanchuk, B. S., Paniagua-Domínguez, R., Minin, I., Minin, O., & Wang, Z. (2017). Refractive index less than two: photonic nanojets yesterday, today and tomorrow [Invited]. Optical Materials Express, 7(6), 1820. doi:10.1364/ome.7.001820Yue, L., Yan, B., Monks, J. N., Dhama, R., Wang, Z., Minin, O. V., & Minin, I. V. (2017). Intensity-Enhanced Apodization Effect on an Axially Illuminated Circular-Column Particle-Lens. Annalen der Physik, 530(2), 1700384. doi:10.1002/andp.201700384Yue, L., Minin, O. V., Wang, Z., Monks, J. N., Shalin, A. S., & Minin, I. V. (2018). Photonic hook: a new curved light beam. Optics Letters, 43(4), 771. doi:10.1364/ol.43.000771Minin, O. V., & Minin, I. V. (2017). Acoustojet: acoustic analogue of photonic jet phenomenon based on penetrable 3D particle. Optical and Quantum Electronics, 49(2). doi:10.1007/s11082-017-0893-yLopes, J. H., Andrade, M. A. B., Leão-Neto, J. P., Adamowski, J. C., Minin, I. V., & Silva, G. T. (2017). Focusing Acoustic Beams with a Ball-Shaped Lens beyond the Diffraction Limit. Physical Review Applied, 8(2). doi:10.1103/physrevapplied.8.024013Minin, I., & Minin, O. (2018). Mesoscale Acoustical Cylindrical Superlens. MATEC Web of Conferences, 155, 01029. doi:10.1051/matecconf/201815501029Pérez-López, S., Fuster, J. M., Candelas, P., Rubio, C., & Belmar, F. (2018). On the use of phase correction rings on Fresnel zone plates with ultrasound piston emitters. Applied Physics Letters, 112(26), 264102. doi:10.1063/1.5036712Liu, C.-Y. (2014). Photonic nanojet shaping of dielectric non-spherical microparticles. Physica E: Low-dimensional Systems and Nanostructures, 64, 23-28. doi:10.1016/j.physe.2014.06.026Li, D., Wang, X., Ling, J., & Yuan, H. (2018). Super-narrow focusing and ultra-long working distance by different shapes of dielectric microlenses. Optik, 160, 138-145. doi:10.1016/j.ijleo.2018.01.061Zhou, Y., Tang, Y., He, Y., Liu, X., & Hu, S. (2018). Effects of immersion depth on super-resolution properties of index-different microsphere-assisted nanoimaging. Applied Physics Express, 11(3), 032501. doi:10.7567/apex.11.03250
Evaluación del uso apropiado de medicamentos en atención primaria. ¿Cómo se puede mejorar?
IntroducciónEl proceso de medicación de un paciente abarca la identificación de su problema de salud, la prescripción para esa indicación por parte del médico, la dispensación farmacéutica y el consumo del fármaco. Los estudios de utilización de medicamentos analizan dicho proceso con el de detectar los factores que alteran el uso correcto de los fármacos.ObjetivoEvaluar la calidad de la prescripción de ciertos medicamentos en atención primaria en función de la indicación para la que fueron prescritos, detectando aquellas características de los pacientes, médicos prescriptores, centros de atención primaria y áreas de salud que influyen en su uso inapropiado.MétodoEstudio prescripción-indicación basado en la estimación de modelos multinivel con bases de datos individualizadas de las prescripciones, que contienen características de las prescripciones, pacientes, médicos, centros de salud y áreas de salud de pertenencia. Estos modelos suponen un avance en este tipo de estudios ya que permiten analizar de forma conjunta la información de distintos niveles y estimar sus respectivas «cuotas de responsabilidad» en la inadecuación de la prescripción.DiscusiónAdemás de su interés metodológico, que puede guiar estudios posteriores, el principal interés del trabajo estriba en su carácter pionero en la utilización masiva de microdatos poblacionales para evaluar la calidad de la prescripción, que proceden de las historias clínicas informatizadas de atención primaria.IntroductionThe process of medicating a patient embraces the identification of the health problem, the doctor’ s prescription to treat this indication, the dispensing of the medicine and its consumption. The studies of use of medicine analyse this process in order to detect those factors that impinge on the correct use of medicines.ObjectiveTo evaluate the quality of the prescription of certain primary care medicines as a function of the indication for which they were prescribed, detecting those features of the patients, prescribing doctors, primary care centre and health district that affect their inappropriate use.MethodPrescription-indication study based on the calculation of multiple-level models with individualised data bases for the prescriptions. These include characteristics of the prescriptions, patients, doctors, health centres and the health district involved. These models are a step forward in this kind of study, in that they enable analysis of the information from different levels at the same time as calculation of the respective «degrees of responsibility» for inadequacies of prescription.DiscussionApart from its methodological originality, which may serve for subsequent studies, the main interest of this study lies in the pioneering nature of its massive use of population micro-data to evaluate prescription quality. These data are taken from the computerised clinical records in primary care
Acción del 2,2-Dimetox¡propano sobre algunos nitratos de metales de transición
En la reacción del 2,2-dimetoxipropano con los nitratos de níquel (II) y cinc hexahidratados se forman los correspondientes nitratos hexametanólicos; en el caso del nitrato de hierro (III) se obtiene nitrato dimetóxido de hierro (III). Se estudian los productos obtenidos por espectrofotometría de absorción en el infrarrojo y por análisis térmico
Effect of exercise on sleep quality and insomnia in middle-aged women: A systematic review and meta-analysis of randomized controlled trials
OBJECTIVE:
We assessed the effects of programmed exercise (PE) on sleep quality and insomnia in middle-aged women (MAW).
METHODS:
Searches were conducted in five databases from inception through December 15, 2016 for randomized controlled trials (RCTs) evaluating the effects of PE versus a non-exercising control condition on sleep quality, sleep disturbance and/or insomnia in MAW. Interventions had to last at least 8 weeks. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) and insomnia with the Insomnia Severity Index (ISI). Random effects models were used for meta-analyses. The effects on outcomes were expressed as mean differences (MDs) and their 95% confidence intervals (CI).
RESULTS:
Five publications reported data from four RCTs on PE effects during 12-16 weeks on sleep quality (n=4 studies reporting PSQI results) and/or insomnia (n=3 studies reporting ISI results), including 660 MAW. Low-moderate levels of exercise significantly lowered the PSQI score (MD=-1.34; 95% CI -2.67, 0.00; p=0.05) compared with controls. In a subgroup analysis, moderate PE (aerobic exercise) had a positive effect on sleep quality (PSQI score MD=-1.85; 95% CI -3.62, -0.07; p=0.04), while low levels of physical activity (yoga) did not have a significant effect (MD-0.46, 95% CI -1.79, 0.88, p=0.50). In three studies (two studies of yoga, one study of aerobic exercise), there was a non-significant reduction in the severity of insomnia measured with the ISI score (MD -1.44, 95% CI -3.28, 0. 44, p=0.13) compared with controls. Heterogeneity of effects among studies was moderate to high.
CONCLUSION:
In middle-aged women, programmed exercise improved sleep quality but had no significant effect on the severity of insomnia.Actividad Física y Deport
Deshidratación y solvatación metanólica del sulfato de níquel heptahidratado. II. Obtención y estudio del NiSO4.3CH3OH
We wish to report the synthesis of a new complex of Ni(II), NiSO4.3CH3OH. The compound has been characterized by elemental analysis, infrared spectra, thermal analysis and magnetic susceptibility measurements. The results indícate that the sulphate group behaves as a bidentate ligand.Se ha preparado un nuevo complejo de Ni(II), NiSO4.3CH3OH. El compuesto ha sido caracterizado por análisis elemental, espectrofotometría de infrarrojo, análisis térmico y medidas de la susceptibilidad magnética. Los resultados indican que el grupo sulfato se encuentra como ligando bidentado
Deshidratación y solvatación metanólica del sulfato de níquel heptahidratado. I. Obtención y estudio del NiSO4.3H2O.3CH3OH
We report here the synthesis of NiSO4.3H2O.3CH3OH. The compound has been characterized by elemental analysis, infrared spectra, thermal analysis and magnetic susceptibility measurements. The results indicate that the sulphate group is ionic.Se describe la síntesis de NiSO4.3H2O.3CH3OH El compuesto ha sido caracterizado por análisis elemental, análisis térmico, espectrofotometría de infrarrojo y medidas de la susceptibilidad magnética. Los resultados indican que el grupo sulfato es iónico
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