PEAKTRAMS: An automated computational approach for the simultaneous detection of features in reverse phase and hilic hrms screening

Comparison of chromatograms obtained in reserved phase (RP) liquid chromatography and hydrophilic interaction liquid chromatography (HILIC) can provide valuable information for the identification and confirmation of suspect and non-target compounds. The plausibility of the obtained chromatographic retention times (RTs) in both modes as well as the ψomparison of the MS/MS spectra are strong points to be considered. This work presents the development of a novel automatic approach for the identification of common peaks between RP and HILIC chromatograms. The core of the program is written in R-project while a simple and user friendly graphical user interface (GUI) was built in JAVA. The first step consists of the introduction of the target chromatograms of the same sample (one obtained by RP and one by HILIC) plus the corresponding blank chromatograms. Blank subtraction was performed first using an algorithm to find in each scan the common m/z features (with a given mass accuracy). This algorithm also considers the RTs (a tolerance interval is applied), so the subtraction takes place even with slight drifts in the RTs between target and blank chromatograms. After blank subtraction, two different lists are obtained with the detected peaks in both RP and HILIC modes. Subsequently, m/z values are compared and matches are listed. The developed workflow was validated with solvent standards and with spiked wastewater samples with a mixture of compounds with a wide range of physicochemical properties. Successful results were obtained for 26 out of the 27 evaluated substances, allowing the recording of the corresponding RTs in both RP and HILIC mode

A Nexafs Study of Nitric Oxide Layers Adsorbed from a nitrite Solution onto a Pt(111) Surface

NO molecules adsorbed on a Pt(111) surface from dipping in an acidic nitrite solution are studied by near edge X-ray absorption fine structure spectroscopy (NEXAFS), X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and scanning tunnelling microscopy (STM) techniques. LEED patterns and STM images show that no long range ordered structures are formed after NO adsorption on a Pt(111) surface. Although the total NO coverage is very low, spectroscopic features in N K-edge and O K-edge absorption spectra have been singled out and related to the different species induced by this preparation method. From these measurements it is concluded that the NO molecule is adsorbed trough the N atom in an upright conformation. The maximum saturation coverage is about 0.3 monolayers, and although nitric oxide is the major component, nitrite and nitrogen species are slightly co-adsorbed on the surface. The results obtained from this study are compared with those previously reported in the literature for NO adsorbed on Pt(111) under UHV conditions

General bounds on non-standard neutrino interactions

We derive model-independent bounds on production and detection non-standard neutrino interactions (NSI). We find that the constraints for NSI parameters are around O(10^{-2}) to O(10^{-1}). Furthermore, we review and update the constraints on matter NSI. We conclude that the bounds on production and detection NSI are generally one order of magnitude stronger than their matter counterparts.Comment: 18 pages, revtex4, 1 axodraw figure. Minor changes, matches published versio

Patterson Function from Low-Energy Electron Diffraction Measured Intensities and Structural Discrimination

Surface Patterson Functions have been derived by direct inversion of experimental Low-Energy Electron Diffraction I-V spectra measured at multiple incident angles. The direct inversion is computationally simple and can be used to discriminate between different structural models. 1x1 YSi_2 epitaxial layers grown on Si(111) have been used to illustrate the analysis. We introduce a suitable R-factor for the Patterson Function to make the structural discrimination as objective as possible. From six competing models needed to complete the geometrical search, four could easily be discarded, achieving a very significant and useful reduction in the parameter space to be explored by standard dynamical LEED methods. The amount and quality of data needed for this analysis is discussed.Comment: 5 pages, 4 figure

Breakdown of anomalous channeling with ion energy for accurate strain determination in gan-based heterostructures

The influence of the beam energy on the determination of strain state with ion channeling in GaN-based heterostructures (HSs) is addressed. Experimental results show that anomalous channeling may hinder an accurate analysis due to the steering effects at the HS interface, which are more intense at lower ion energies. The experimental angular scans have been well reproduced by Monte Carlo simulations, correlating the steering effects with the close encounter probability at the interface. Consequently, limitations in the determination of the strain state by ion channeling can be overcome by selecting the adequate beam energy

Global Analysis of the post-SNO Solar Neutrino Data for Standard and Non-Standard Oscillation Mechanisms

What can we learn from solar neutrino observations? Is there any solution to the solar neutrino anomaly which is favored by the present experimental panorama? After SNO results, is it possible to affirm that neutrinos have mass? In order to answer such questions we analyze the current available data from the solar neutrino experiments, including the recent SNO result, in view of many acceptable solutions to the solar neutrino problem based on different conversion mechanisms, for the first time, using the same statistical procedure. This allows us to do a direct comparison of the goodness of the fit among different solutions, from which we can discuss and conclude on the current status of each proposed dynamical mechanism. These solutions are based on different assumptions: (a) neutrino mass and mixing, (b) non-vanishing neutrino magnetic moment, (c) the existence of non-standard flavor-changing and non-universal neutrino interactions and (d) the tiny violation of the equivalence principle. We investigate the quality of the fit provided by each one of these solutions not only to the total rate measured by all the solar neutrino experiments but also to the recoil electron energy spectrum measured at different zenith angles by the Super-Kamiokande collaboration. We conclude that several non-standard neutrino flavor conversion mechanisms provide a very good fit to the experimental data which is comparable with (or even slightly better than) the most famous solution to the solar neutrino anomaly based on the neutrino oscillation induced by mass.Comment: Minor changes in the solar magnetic field profile used, and some refferences added. Final version to appear in PR

SELENE. INFORMATIZACIÓN DE LA HISTORIA CLÍNICA ELECTRÓNICA: IMPLICACIÓN SOBRE EL PROCESO DE ENFERMERÍA.

This article talks about the changeover to a corporative hospital documentation system, which gives computer solutions in order to resolve the global clinic problem from the point of view of all the assistencial setting participants, and which allows an improvement of the resources management. This documentation system is an assistencial, an administrative management and a sanitary management tool. This documentation system change incluyes the implantation of the Electronic Clinical History, making a reference to the Infirmary registers, doing a documentary normalization which includes the emplantation of the Infirmary methodology through the Nanda, Nic and Noc taxonomies.Este artículo trata sobre el cambio hacia un sistema de información hospitalario corporativo, que implementa soluciones informáticas para tratar de resolver la problemática clínica global desde el punto de vista de todos los partícipes del escenario asistencial y que permiten una mejora en la gestión de los recursos implicados. Siendo una herramienta asistencial, una herramienta de gestión administrativa y una herramienta de gestión sanitaria. Ese cambio de sistema de información engloba la implantación de la Historia Clínica Electrónica (herramienta asistencial), haciendo especial referencia a la informatización de los registros que realiza Enfermería, realizando para ello una normalización documental que incluye entre otras cosas la implantación de la metodología de Enfermería a través de taxonomías Nanda, Nic y Noc

Identification of biotransformation products of citalopram formed in activated sludge

Citalopram (CTR) is a highly consumed antidepressant which is removed incompletely by conventional wastewater treatment. Although it is highly detected in effluent wastewaters, little is known about its behavior and transformation processes that undergo during wastewater treatment. The present study aims to expand the knowledge on fate and transformation of CTR during the biological breakdown process. For this purpose, biotransformation batch reactors were set up to assess biotic, abiotic and sorption losses of this compound. One of the main objectives of the study was the identification of the formed transformation products (TPs) by applying suspect and non-target strategies based on liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). In this regard, the complementary use of reversed phase chromatography (RP) and hydrophilic interaction liquid chromatography (HILIC) in the identification of polar TPs, the deep evaluation of the obtained MS/MS spectra, as well as the use of in-house developed quantitative structure-retention relationship (QSRR) retention time prediction models provided valuable support to identification. Fourteen TPs were detected. Thirteen of them were tentatively identified. Four compounds were confirmed (N-desmethylCTR, CTR amide, CTR carboxylic acid and 3-oxo-CTR) through the purchase of the corresponding reference standard. Probable structures based on diagnostic evidence were proposed for the additional nine TPs. A transformation pathway for the biotransformation of CTR was proposed. The presence of the identified TPs was assessed in real wastewater samples through retrospective analysis resulting in the detection of five compounds. Finally, the potential ecotoxicological risk posed by CTR and its TPs to different trophic levels of aquatic organisms, exposed to the studied effluents, was evaluated by means of risk quotients