Performance of ophthalmic artery Doppler velocimetry in the complementary diagnosis of preeclampsia.

OBJECTIVES: To calculate the accuracy (A) and establish the best cutoff value for ophthalmic artery (OA) Doppler velocimetry indexes in patients diagnosed with preeclampsia (PE), compared with healthy pregnant women. METHODS: This prospective experimental study enrolled 268 women: 133 with PE and 135 healthy pregnant women. All patients were evaluated by OA Doppler sonography, bilaterally, to assess their pulsatility index (PI), resistance index (RI), peak systolic velocity (PVS), second peak systolic velocity (P2), end-diastolic velocity (EDV), and peak ratio (PR). Means were compared using Student's T-test. Receiver Operating Characteristics (ROC) curve was used to establish the cutoff value and estimate the sensitivity (S), specificity (Sp), accuracy (A) of all variables, and a significance of 95% was adopted. RESULTS: ROC curve analysis showed that P2 and PR were superior to the other parameters for PE diagnosis. We tested two cutoff values: (1) using PR ≥0.70, obtained A: 88.72%, S: 81.95%, and Sp: 95.48% and (2) using PR ≥0.75, and A: 86.24%, S: 74.43%, and Sp: 99.24%. By adopting P2 ≥ 21.5 cm/s, we obtained A: 87.59%, S: 84.96%, and Sp: 90.22% and when the cutoff point was P2 ≥ 22 cm/s, there was a slight decrease in A to 86.46% and S to 81.20%, with Sp: 91.89.3%. CONCLUSION: Ophthalmic artery Doppler demonstrated to be an effective and high-performance imaging method for the diagnosis of PE and the indexes P2 and PR demonstrated superior accuracy to the other Doppler parameters assessed. Higher performance occurred when the cutoff values with greater specificity were adopted, PR ≥ 0.75 and P2 ≥ 22 cm/s, considering that the proposed OA Doppler is to be a complementary method for preeclampsia.

Possible effects of clustering structure in the competition between fast emission processes and compound nucleus decay / Posibles efectos de estructura de agrupamiento en la competencia entre los procesos de emisión rápida y desintegración del núcleo compuesto

Abstract The attention to nuclear clustering has been renewed due to the study of weakly bound nuclei at the drip lines. In particular, clustering structural properties in medium-mass systems have been studied by looking at the competition between the evaporation and pre-equilibrium particle emission in central collisions. Although for light nuclei at an excitation energy close to the particle separation value there are experimental evidence of such structure effects, this is still not the case for heavier systems since the determination of pre-formed clusters within nuclear matter is less obvious. Two systems, leading to the same 81Rb* compound nucleus, have been studied at the same beam velocity 16 AMeV: 16O + 65Cu and 19F + 62Ni. The experiment has been performed using the GARFIELD + RCo detection system installed at the Legnaro National Laboratories.Light charged particles energy distributions and multiplicities have been compared with different statistical and dynamical model calculations. From the first comparison between the two systems a difference in the fast α-decay channel has been evidenced, which can be related to the difference in the projectile structure. Recent data analysis results and comparisons with model calculations are presented in this contribution.

Resumen La atención a la agrupación nuclear se ha renovado debido al estudio de núcleos débilmente unidos en las líneas de goteo. En particular, se han estudiado las propiedades estructurales del agrupamiento en sistemas de masa media al observar la competencia entre la evaporación y la emisión de partículas de preequilibrio en colisiones centrales. Aunque para núcleos ligeros a una energía de excitación cercana al valor de separación de la partícula hay evidencia experimental de tales efectos de estructura, este no es el caso para sistemas más pesados ya que la determinación de agrupamientos preformados dentro de la materia nuclear es menos obvia. Se han estudiado dos sistemas, que conducen al mismo núcleo compuesto 81Rb *, a la misma velocidad de haz 16 AMeV: 16O + 65Cu y 19F + 62Ni. El experimento se ha realizado utilizando el sistema de detección GARFIELD + RCo instalado en los Laboratorios Nacionales Legnaro. Las distribuciones de energía y las multiplicidades de partículas de carga ligera se han comparado con diferentes cálculos de modelos estadísticos y dinámicos. Desde la primera comparación entre los dos sistemas, se ha evidenciado una diferencia en el canal de desintegración α rápida, que se puede relacionar con la diferencia en la estructura del proyectil. En esta contribución se presentan los resultados del análisis de datos recientes y las comparaciones con los cálculos del modelo.