To estimate the accuracy of the transcutaneous carbon dioxide tension measurement (PtCO(2)) compared to the measurement of the arterial carbon dioxide tension (PaCO(2)).
An analytical, longitudinal, ...prospective and observational study, of a dynamic cohort taken from the in-patients of a Paediatric Intensive Care Unit (PICU). The PtCO(2) was measured with the SenTec AG analyzer, and the sensor was applied with the specific Multi-Site Attachment Ring. PtCO(2) and PaCO(2) were recorded at the same time. The statistical significance of the association between paired measurements was evaluated with the Snedecor's F test, the Pearson's r(2) correlation coefficient and the Interclass Correlation Coefficient (ICC). The degree of agreement was evaluated with the Bland & Altman method. The consistency of the results was evaluated with the ANalysis Of the VAriance (ANOVA).
One hundred and six paired measurements, PtCO(2) and PaCO(2), from twelve patients, were compared. The means of the PaCO(2) and PtCO(2) were 51.0+/-13mmHg and 50.1+/-14mmHg, respectively; r(2)=0.87 (p<0.001), ICC=0.96, (95% CI: 0.94-0.97). The Bland-Altman analysis showed a mean difference of-0.9mmHg (95% CI:-2.0 to 0.2mmHg). The correlation was better in cases with no respiratory disease, with low respiratory assistance, with PaCO(2)>50mmHg and with the sensor applied on the forehead. The results were consistent. No side effects derived from the use of the ring were observed.
The correlation between PtCO(2) and PaCO(2) is excellent and stable. The ring sensor was safe and easy to use.
If neutrinos are their own antiparticles, the otherwise-forbidden nuclear reaction known as neutrinoless double beta decay (\(\beta\beta 0\nu\)) can occur, with a characteristic lifetime which is ...expected to be very long, making the suppression of backgrounds a daunting task. It has been shown that detecting (``tagging'') the Ba\(^{+2}\) dication produced in the double beta decay \({}^{136}\mathrm{Xe} \rightarrow {}^{136}\)Ba\(^{+2}+ 2 e + (2 \nu)\) in a high pressure gas experiment, could lead to a virtually background free experiment. To identify these \Bapp, chemical sensors are being explored as a key tool by the NEXT collaboration . Although used in many fields, the application of such chemosensors to the field of particle physics is totally novel and requires experimental demonstration of their suitability in the ultra-dry environment of a xenon gas chamber. Here we use a combination of complementary surface science techniques to unambiguously show that Ba\(^{+2}\) ions can be trapped (chelated) in vacuum by an organic molecule, the so-called fluorescent bicolour indicator (FBI) (one of the chemosensors developed by NEXT), immobilized on a surface. We unravel the ion capture mechanism once the molecules are immobilised on Au(111) surface and explain the origin of the emission fluorescence shift associated to the trapping of different ions. Moreover, we prove that chelation also takes place on a technologically relevant substrate, as such, demonstrating the feasibility of using FBI indicators as building blocks of a Ba\(^{+2}\) detector.
Carbon nanotubes are a good realization of one-dimensional crystals where basic science and potential nanodevice applications merge. Defects are known to modify the electrical resistance of carbon ...nanotubes; they can be present in as-grown carbon nanotubes, but controlling their density externally opens a path towards the tuning of the electronic characteristics of the nanotube. In this work, consecutive Ar+ irradiation doses are applied to single-walled nanotubes (SWNTs) producing a uniform density of defects. After each dose, the room-temperature resistance versus SWNT length (R(L)) along the nanotube is measured. Our data show an exponential dependence of R(L) indicating that the system is within the strong Anderson localization regime. Theoretical simulations demonstrate that mainly di-vacancies contribute to the resistance increase induced by irradiation, and that just a 0.03% of di-vacancies produces an increase of three orders of magnitude in the resistance of a SWNT of 400 nm length.
Radio-frequency (RF) carpets with ultra-fine pitches are examined for ion transport in gases at atmospheric pressures and above. We develop new analytic and computational methods for modeling RF ion ...transport at densities where dynamics are strongly influenced by buffer gas collisions. An analytic description of levitating and sweeping forces from phased arrays is obtained, then thermodynamic and kinetic principles are used to calculate ion loss rates in the presence of collisions. This methodology is validated against detailed microscopic SIMION simulations. We then explore a parameter space of special interest for neutrinoless double beta decay experiments: transport of barium ions in xenon at pressures from 1 to 10 bar. Our computations account for molecular ion formation and pressure dependent mobility as well as finite temperature effects. We discuss the challenges associated with achieving suitable operating conditions, which lie beyond the capabilities of existing devices, using presently available or near-future manufacturing techniques.
A
bstract
The
Neutrino Experiment with a Xenon TPC
(NEXT) searches for the neutrinoless double-beta (0
νββ
) decay of
136
Xe using high-pressure xenon gas TPCs with electroluminescent amplification. ...A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0
νββ
decay better than 10
27
years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.
Absence of dc-conductivity in lambda-DNA de Pablo, P J; Moreno-Herrero, F; Colchero, J ...
Physical review letters,
12/2000, Letnik:
85, Številka:
23
Journal Article
Recenzirano
The electrical conductivity of biomaterials on a molecular scale is of fundamental interest in the life sciences. We perform first principles electronic structure calculations, which clearly indicate ...that lambda-DNA chains should present large resistance values. We also present two direct procedures to measure electrical currents through DNA molecules adsorbed on mica. The lower limit for the resistivity is 10(6) Omega . cm, in agreement with our calculations. We also show that low energy electron bombardment induces a rapid contamination and dramatically affects the measured conductivity, thus providing an explanation to recent reports of high DNA conductivity.
We investigate the solar phenomena associated with the origin of the solar energetic particle (SEP) event observed on 2013 April 11 by a number of spacecraft distributed in the inner heliosphere over ...a broad range of heliolongitudes. We use extreme ultraviolet (EUV) and white-light coronagraph observations from the Solar Dynamics Observatory (SDO), the SOlar and Heliospheric Observatory, and the twin Solar TErrestrial RElations Observatory spacecraft (STEREO-A and STEREO-B) to determine the angular extent of the EUV wave and coronal mass ejection (CME) associated with the origin of the SEP event. We show that the west flank of the CME-driven shock propagating at high altitudes above the solar surface was most likely the source of the particles observed near Earth, but it did not leave any EUV trace on the solar disk.
El objetivo de este trabajo ha sido realizar un estudio de utilización de analgésicos opiáceos en el Hospital Universitario La Paz (Madrid) en el año 2008 para conocer cómo se está utilizando este ...grupo de medicamentos y cuál es la tendencia del consumo. Para ello, se presentan los datos de uso de opiáceos en pacientes ingresados de forma global, por hospitales y por servicios clínicos. Se exponen los datos de consumo de los 5 últimos años y se ha cuantificado el uso del resto de principios activos empleados como analgésicos en nuestro hospital.
Haciendo uso de la metodología recomendada por la Organización Mundial de la Salud para los estudios de utilización de medicamentos en hospitales, presentamos nuestros datos en dosis diarias definidas (DDD) por 100 estancias. Los datos de consumo se han obtenido del programa de gestión de medicamentos del Servicio de Farmacia Farma Tools (Dominion
®)
El valor global de utilización de opiáceos en 2008 ha sido de 8,1 DDD/100 estancias. Los principios activos más consumidos han sido la morfina parenteral y el fentanilo transdérmico, y entre los 2 representan el 83% del consumo total de opiáceos. En el análisis por hospitales apreciamos que el Hospital General y el de Traumatología son los que presentan un mayor empleo de opiáceos y siguen el mismo patrón de utilización que el global. Los servicios más representativos del consumo de opiáceos han sido las reanimaciones del Hospital General y de Traumatología, los Servicios de Oncología, Cuidados paliativos y Hematología. En estos últimos 5 años se ha producido un incremento global del consumo de aproximadamente el 20%, viéndose implicados todos los principios activos. Con relación al consumo total de analgésicos, los datos reflejan una amplia utilización en el hospital (104 DDD/100 estancias). Los opiáceos representan un 7,4% del consumo total de analgésicos, siendo el paracetamol y el metamizol los analgésicos más ampliamente utilizados.
Los datos de nuestro estudio reflejan una tendencia al incremento del consumo de opiáceos en el hospital, lo que consideramos una mejora en el tratamiento del dolor, tanto agudo como crónico, pues en este incremento se ven involucrados todos los principios activos opiáceos. En un hospital con elevada actividad y complejidad asistencial como el Hospital La Paz, este tipo de estudios constituyen una herramienta que nos permite conocer y comparar el uso de opiáceos en los distintos hospitales y servicios clínicos. Nos permiten conocer la evolución del consumo así como detectar posibles desviaciones e implementar acciones de mejora en los diferentes servicios clínicos implicados en el tratamiento del dolor.
The aim of this study was to analyze opioid analgesic use in the La Paz University Hospital in 2008 in order to identify patterns of use and consumption. To that end, data from inpatients were analyzed overall, as well as by hospitals and departments. We analyzed data on consumption in the previous 5 years and quantified the use of the remaining active principles administered as analgesics in our hospital.
Following the Wold Health Organization's guidelines for studies on medication use in hospitals, data are shown as defined daily dose (DDD) per 100 hospital stays. Data on drug use were obtained from the drug management program, Farma Tools (Dominion®), which is used by the Pharmacy Service at La Paz Hospital.
The overall value of opioid utilization in 2008 was 8.1 DDD per 100 hospital stays. The most widely used active principles were parenteral morphine and transdermal fentanyl. Together, these drugs represented 83% of total opioid consumption. Analysis by hospital revealed that the General and Traumatology Hospitals showed the highest opioid drug consumption and followed the same utilization pattern as overall use. The services most representative of opioid consumption in inpatients were the Recovery Room in the General and Traumatology Hospitals, Critical Care, Oncology, Hematology and Palliative Care. In the last 5 years of the study, the overall use of these drugs increased by 20%, irrespective of the active principles involved. Analysis of analgesic intake at La Paz Hospital showed widespread use (104 DDD per 100 hospital stays). Opioids represented 7.4% of total analgesic consumption, the most frequently used analgesics being acetaminophen and metamizol.
The results of our study show an increasing trend in opioid consumption in this hospital. We believe this increase reflects an improvement in the management of both acute and chronic pain, since the use of all opioid active ingredients increased. In hospitals with very high activity and complex clinical work, such as La Paz Hospital, this kind of study constitutes a specific tool that allows opioid use in distinct services and hospitals to be compared. This type of study also allows patterns of consumption and possible deviations to be identified and improvements to be made in the distinct clinical services involved in treating pain.
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