Correlated ion and neutral time of flight technique combined with velocity map imaging: Quantitative measurements for dissociation processes in excited molecular nano-systems.

The combination of the Dispositif d'Irradiation d'Agrégats Moléculaire with the correlated ion and neutral time of flight-velocity map imaging technique provides a new way to explore processes occurring subsequent to the excitation of charged nano-systems. The present contribution describes in detail the methods developed for the quantitative measurement of branching ratios and cross sections for collision-induced dissociation processes of water cluster nano-systems. These methods are based on measurements of the detection efficiency of neutral fragments produced in these dissociation reactions. Moreover, measured detection efficiencies are used here to extract the number of neutral fragments produced for a given charged fragment.

Measurement of the velocity of neutral fragments by the "correlated ion and neutral time of flight" method combined with "velocity-map imaging".

In the challenging field of imaging molecular dynamics, a novel method has been developed and implemented that allows the measurement of the velocity of neutral fragments produced in collision induced dissociation experiments on an event-by-event basis. This has been made possible by combining a correlated ion and neutral time of flight method with a velocity map imaging technique. This new method relies on a multiparametric correlated detection of the neutral and charged fragments from collision induced dissociation on one single detector. Its implementation on the DIAM device (Device for irradiation of biomolecular clusters) (Dispositif d'Irradiation d'Agrégats bioMoléculaires) allowed us to measure the velocity distribution of water molecules evaporated from collision induced dissociation of mass- and energy-selected protonated water clusters.

A novel "correlated ion and neutral time of flight" method: event-by-event detection of neutral and charged fragments in collision induced dissociation of mass selected ions.

A new tandem mass spectrometry (MS/MS) method based on time of flight measurements performed on an event-by-event detection technique is presented. This "correlated ion and neutral time of flight" method allows to explore Collision Induced Dissociation (CID) fragmentation processes by directly identifying not only all ions and neutral fragments produced but also their arrival time correlations within each single fragmentation event from a dissociating molecular ion. This constitutes a new step in the characterization of molecular ions. The method will be illustrated here for a prototypical case involving CID of protonated water clusters H(+)(H2O)n = 1-5 upon collisions with argon atoms.

A new experimental setup designed for the investigation of irradiation of nanosystems in the gas phase: a high intensity mass-and-energy selected cluster beam.

DIAM (Dispositif d'Irradiation d'Agrégats Moléculaires) is a new experimental setup devoted to investigate processes induced by irradiation at the nanoscale. The DIAM apparatus is based on a combination of techniques including a particle beam from high-energy physics, a cluster source from molecular and cluster physics, and mass spectrometry form analytical sciences. In this paper, we will describe the first part of the DIAM apparatus that consists of an ExB double spectrometer connected to a cluster ion source based on a continuous supersonic expansion in the presence of ionizing electrons. This setup produces high intensities of energy-and-mass selected molecular cluster ion beams (1000 s of counts s(-1)). The performance of the instrument will be shown through measurements of 6-8 keV beams of protonated water clusters, (H(2)O)(n)H(+) (n = 0-21) and mixed protonated (or deprotonated) water-pyridine cluster ions: PyrH(+)(H(2)O)(n) (n = 0-15), Pyr(2)H(+) (H(2)O)(n) (n = 0-9), and (Pyr-H)(+) (H(2)O).

[Characteristics of diagnoses of malignant neoplasms in primary care]. / Características del diagnóstico de las neoplasias malignas en atención primaria.

OBJECTIVE: To describe the diagnostic process of malignant neoplasms according to the level of care, initial symptoms and diagnostic procedures.Design. Retrospective descriptive study. SETTING: Health centre on the periphery of a big city. PARTICIPANTS: Cases of malignant neoplasms recorded between 1990 and 2000 through the mortality register and specific recording in 2000. MAIN MEASUREMENTS: We reviewed the records, obtaining age and gender, location, initial symptoms, date of first consultation and at what care level, diagnostic tests requested in primary care (PC) and the time elapsed until they became available, until the patients referral and until the definitive diagnosis. 274 cases were included, with information lacking for 12. RESULTS: 42.4% were women, with average age 67.6. The most frequent types of cancer were digestive, respiratory and masculine genital-urinary. 75.2% consulted initially in PC. The most common symptoms were pain and haemorrhage. Of those attended in PC, diagnostic tests were requested for 46.7%, the most common of these being basic analysis (53.2%) and simple x-ray (24.8%). Mean time before results were available was 15.4 days. 67.2% of all cases were referred. Mean time from consultation to referral was 7.3 days; and to definitive diagnosis, 68.0 days. However, for those initially attended in PC, the mean wait was 81.0 days; and at other levels, 30 days (P<.0001). CONCLUSIONS: Most patients consult on their initial symptoms in PC. The time taken for the diagnostic process at this level is adequate, although the total length of the process is greater for those who first consulted in PC.

Características del diagnóstico de las neoplasias malignas en atención primaria / Characteristics of diagnoses of malignant neoplasms in primary care

Objetivo. Describir el proceso diagnóstico de las neoplasias malignas según el nivel asistencial, síntomas iniciales y procedimientos diagnósticos. Diseño. Estudio descriptivo, retrospectivo. Emplazamiento. Centro de salud de la periferia de una gran ciudad. Participantes. Casos de neoplasias malignas registrados desde 1990 hasta 2000 mediante fichero de mortalidad y registro específico durante el año 2000.Mediciones principales. Revisamos las historias, obteniendo edad y género, localización, síntomas iniciales, fecha de primera consulta y nivel asistencial de ésta, pruebas diagnósticas solicitadas en atención primaria (AP) y tiempo hasta que están disponibles, hasta la derivación del paciente y hasta el diagnóstico definitivo. Se incluyeron 274 casos, careciéndose de información en 12.Resultados. Un 42,4 por ciento eran mujeres; su edad media fue 67,6 años. Las localizaciones más frecuentes fueron en aparato digestivo, respiratorio y genitourinario masculino. El 75,2 por ciento consultó inicialmente en AP. Los síntomas más frecuentes fueron dolor y hemorragia. De los atendidos en AP, se solicitaron pruebas diagnósticas en un 46,7 por ciento, y las más utilizadas fueron la analítica básica (53,2 por ciento) y la radiografía simple (24,8 por ciento); la mediana de tiempo que se tardó en disponer de resultados fue de 15,4 días. Se derivó un 67,2 por ciento de todos los casos. La mediana de tiempo desde consulta hasta derivación fue de 7,3 días y hasta el diagnóstico definitivo de 68,0 días, aunque para los atendidos inicialmente en AP la mediana fue de 81,0 días y de 30,0 si consultaron en otros niveles (p < 0,0001).Conclusiones. Los pacientes consultan los síntomas iniciales mayoritariamente en AP, y la duración del proceso diagnóstico en este nivel es adecuada, aunque la duración total del proceso es mayor en quienes consultan en AP (AU)