Photonically referenced extremely stable oscillator.

Due to their low phase noise at high carrier frequencies, photonic microwave oscillators are continuously expanding their application areas including digital signal processing, telecommunications, radio astronomy, and RADAR and LIDAR systems. Currently, the lowest noise photonic oscillators rely on traditional optical frequency combs with multiple stabilization loops that incorporate large vacuum components and complex optoelectronic configurations. Hence, the resulting systems are not only challenging to operate but also expensive to maintain. Here, we introduce a significantly simpler solution: a Photonically Referenced Extremely STable Oscillator (PRESTO). PRESTO requires only three key components: a femtosecond laser, a fiber delay element, and a pulse timing detector. The generated microwave at 10 GHz has phase noise levels of -125, -145, and <-160 dBc/Hz at 1, 10, and >100 kHz, respectively, with an integrated timing jitter of only 2 fs root mean square (RMS) over [100 Hz-1 MHz]. This approach offers a reliable solution for simplifying and downsizing photonic oscillators while delivering high performance.

Large-mode-area soliton fiber oscillator mode-locked using NPE in an all-PM self-stabilized interferometer.

In this work, we investigate an approach to scale up the output pulse energy in an all-polarization-maintaining 17.3 MHz Yb-doped fiber oscillator via implementation of a 25 µm core-diameter large-mode-area fiber. The artificial saturable absorber is based on a Kerr-type linear self-stabilized fiber interferometer, enabling non-linear polarization rotation in polarization-maintaining fibers. Highly stable mode-locked steady states in the soliton-like operation regime are demonstrated with 170 mW average output power and a total output pulse energy of ∼10n J distributed between two output ports. An experimental parameter comparison with a reference oscillator constructed with 5.5 µm core-sized standard fiber components reveals an increase of pulse energy by a factor of 36 with simultaneously reduced intensity noise in the high-frequency range >100k H z.

Leucemia mieloide crónica en crisis blástica: perspectiva terapéutica según la evidencia (Parte II) / Chronic myelogenous leukemia in blastic phase: therapeutic perspective according to clinical evidence (Part II)

En la actualidad, el pronóstico de los pacientes con crisis blástica (CB) es pobre y depende, especialmente, de lograr una respuesta completa, con una mediana de supervivencia entre los tres y los doce meses, independientemente del fenotipo de la enfermedad. Hasta el momento, no existe un tratamiento estándar para la CB, que habitualmente manifiesta un curso similar al de las leucemias agudas quimiorresistentes; las aproximaciones más recientes han mostrado que el uso de regímenes similares a los empleados en el manejo de las leucemias agudas asociados al imatinib permiten mejorar las tasas de supervivencia global y libres de progresión de la enfermedad. No obstante, los pacientes con esta condición deberán ser considerados candidatos para estudios experimentales. A pesar de que la posibilidad de lograr respuesta completa es baja, la población que logra llegar a ella deberá consolidarse con trasplante alogénico de médula ósea. Un grupo de expertos conformado por hematólogos, oncólogos y epidemiólogos clínicos de Bogotá D. C., Colombia, se encargó de revisar y seleccionar la mejor evidencia sobre el diagnóstico y tratamiento de la CB. La información se obtuvo a partir de búsquedas estructuradas realizadas en MedLine, Embase, Cochrane, Biosis, Cinhal, Lilacs y de varios registros de experimentos clínicos en curso. Este documento presenta las principales conclusiones y algunas recomendaciones para mejorar los principales desenlaces de la CB, y permitir así la toma de decisio- nes basadas en la mejor evidencia, que promoverá el uso racional de los recursos en salud.

Chronic myelogenous leukemia traditionally has been characterized by a biphasic or triphasic course. Blastic phase overall prognosis is poor, with a median survival of 3 to 12 months. Approximately 50% of patients have a myeloid phenotype, 25% have a lymphoid phenotype, and 25% have an undifferentiated phenotype. There is currently no standard treatment for the blastic phase of chronic myeloid leukemia, which is a chemoresistant form of acute leukemia. Current approaches include using standard acute myeloid leukemia regimens associated with imatinib in an effort to induce remission, variations of these approaches with drugs that seem more active in this specific leukemia, and the direct entry of patients into studies of investigational agents. Although the likelihood of achieving remission is small, immediate bone marrow transplantation in remission should be considered because it provides the only opportunity for long-term survival at this time. An expert panel of hematologists, oncologists and clinical epidemiologists of Bogotá, D.C., Colombia reviewed selected literature related with BP of chronic myeloid leukemia obtained from advanced searches of medial literature in MedLine, Embase, Cochrane, Biosis, Cinhal, Lilacs and from several in course clinical trials databases. The following document present the principal conclusions and some recommendations to improve outcomes of BP, to assist practitioners to apply the best available research evidence to clinical decisions, and to promote responsible use of health care resources.