Selective Reagent Ion Mass Spectrometric Investigations of the Nitroanilines

This paper presents an investigation of proton and charge transfer reactions to 2-, 3- and 4-nitroanilines (C6H6N2O2) involving the reagent ions H3O+·(H2O)n (n=0, 1 and 2) and O2+, respectively, as a function of reduced electric field (60-240 Td), using Selective Reagent Ion-Time-of-Flight-Mass Spectrometry (SRI-ToF-MS). To aid in the interpretation of the H3O+·(H2O)n experimental data, the proton affinities and gas-phase basicities for the three nitroaniline isomers have been determined using density functional theory. These calculations show that proton transfer from both the H3O+ and H3O+·H2O reagent ions to the nitroanilines will be exoergic and hence efficient, with the reactions proceeding at the collisional rate. For proton transfer from H3O+ to the NO2 sites, the exoergicities are 171 kJ mol-1 (1.8 eV), 147 kJ mol-1 (1.5 eV) and 194 kJ mol-1 (2.0 eV) for 2-, 3- and 4-nitroanilines, respectively. Electron transfer from all three of the nitroanilines is also significantly exothermic by approximately 4 eV. Although a substantial transfer of energy occurs during the ion/molecule reactions, the processes are found to predominantly proceed via non-dissociative pathways over a large reduced electric field range. Only at relatively high reduced electric fields (>180 Td) is dissociative proton and charge transfer observed. Differences in fragment product ions and their intensities provide a means to distinguish the isomers, with proton transfer distinguishing 2-nitroaniline (2-NA) from 3- and 4-NA, and charge transfer distinguishing 4-NA from 2- and 3-NA, thereby providing a means to enhance selectivity using SRI-ToF-MS.(VLID)4826158Version of recor

Magnetic-dipole spin effects in noncommutative quantum mechanics

A general three-dimensional noncommutative quantum mechanical system mixing spatial and spin degrees of freedom is proposed. The analogous of the harmonic oscillator in this description contains a magnetic dipole interaction and the ground state is explicitly computed and we show that it is infinitely degenerated and implying a spontaneous symmetry breaking. The model can be straightforwardly extended to many particles and the main above properties are retained. Possible applications to the Bose-Einstein condensation with dipole-dipole interactions are briefly discussed.Instituto de Física La Plat

Análisis del plano sagital en las escoliosis idiopáticas tratadas con instrumentación Cotrel-Dubousset

Se analiza la evolución del plano sagital en 50 enfermos con escoliosis idiopática intervenidos mediante artrodesis posterior con instrumentación de Cotrel-Dubousset con un seguimiento medio de 72 meses. Se recogieron los valores evolutivos de cifosis torácica medida entre T5 y T12 y de lordosis lumbar medida entre Ll y L5. Las curvas escolióticas fueron clasificadas según King et al. Los resultados obtenidos mostraron que no existía una variación global significativa de la cifosis torácica tras la cirugía. Sólo en aquellos enfermos que previamente existía una hipocifosis torácica existía una mejoría estadísticamente significativa de la misma con la intervención. Se evidenció una clara tendencia al incremento de la cifosis torácica con el tiempo. La lordosis lumbar se mantuvo, en la mayoría de los casos, dentro de límites fisiológicos. La instrumentación de Cotrel-Dubousset ofrece ventajas evidentes respecto a instrumentaciones previas en lo que respecta a la obtención de una curva más fisiológica en el plano sagital. Permite corregir la hipocifosis torácica severa y mantener la lordosis lumbar dentro de límites normales, incluso en instrumentaciones por debajo de L3.Sagittal plane analysis of 50 patients with idiopathic scoliosis treated with Cotrel- Dubousset instrumentation was performed. Mean follow-up was 72 months. The values of thoracic kyphosis from T5 to T12 and lumbar lordosis from L1 to L5 were retrospectively reviewed. Scoliotic curves were classified according to King et al. The results showed that there was not any significant change in thoracic kyphosis after surgery. Only those patients with preoperative thoracic hypokyphosis achieved a significant realignment. There was an obvious increase of thoracic kyphosis with time. Lumbar lordosis was maintained within normal limits in the mayority of patients. Cotrel-Dubousset instrumentation achieves better sagittal alignment than previous systems. It corrects thoracic hypokyphosis and preserves lumbar lordosis, even when the instrumentation is carried out lower than L3

Detection of Temporality at Discourse Level on Financial News by Combining Natural Language Processing and Machine Learning

Finance-related news such as Bloomberg News, CNN Business and Forbes are valuable sources of real data for market screening systems. In news, an expert shares opinions beyond plain technical analyses that include context such as political, sociological and cultural factors. In the same text, the expert often discusses the performance of different assets. Some key statements are mere descriptions of past events while others are predictions. Therefore, understanding the temporality of the key statements in a text is essential to separate context information from valuable predictions. We propose a novel system to detect the temporality of finance-related news at discourse level that combines Natural Language Processing and Machine Learning techniques, and exploits sophisticated features such as syntactic and semantic dependencies. More specifically, we seek to extract the dominant tenses of the main statements, which may be either explicit or implicit. We have tested our system on a labelled dataset of finance-related news annotated by researchers with knowledge in the field. Experimental results reveal a high detection precision compared to an alternative rule-based baseline approach. Ultimately, this research contributes to the state-of-the-art of market screening by identifying predictive knowledge for financial decision making