RESUMEN
A diastereoselective, DABCO-catalyzed reaction of isatin-derived ketimines with allenoates is described. Exploiting the stereodirecting effect of the bulky tert-butanesulfinyl chiral auxiliary, the method provides an efficient access to single diastereoisomers of unprecedented spirocyclic oxindoles, bearing a 4-methyleneazetidine ring at the spiro junction. The versatility of the method is fully demonstrated by further transformations including the conversion to relevant spirocyclic oxindolo-ß-lactams.
RESUMEN
We propose an on-board selection scheme for aerial and space images, based on linear feature detection in a feature hyperspace. The detection task is performed by means of the Radon transform (RT) and the wavelet transform; a fast algorithm for the RT computation is described, and counteractions against the discretization errors are proposed. A new, wavelet-based algorithm is introduced, which performs a fine analysis of the waveforms of the RT peaks, yielding a possibly error-free detection in images corrupted by a high level of noise. A technique, based on the feature hyperspace, is proposed, able to significantly exploit all the available pieces of information on these peaks. Results of the tests on synthetic and real images are reported, which show that this method achieves satisfactory results, making the detection task highly reliable in the presence of both noise and clutter.
RESUMEN
The authors present a case of prenatal diagnosis of cloacal anomaly, characterized by the presence of oligohydramnios and cystic pelvic mass with changing features during observation. Postnatal study confirmed the presence of a recto-cloacal fistula, with a high confluence of the urinary, genital and intestinal systems. Both parents had a chromosome 9 inversion (p11q13), but the child was chromosomally normal.
Asunto(s)
Cloaca/anomalías , Enfermedades Fetales/diagnóstico por imagen , Fístula , Fístula Rectal/congénito , Adulto , Aberraciones Cromosómicas , Cromosomas Humanos Par 9 , Cloaca/diagnóstico por imagen , Cistoscopía , Femenino , Humanos , Embarazo , Diagnóstico Prenatal , Ultrasonografía Prenatal , Anomalías Urogenitales/diagnóstico por imagenRESUMEN
The authors used the Zeiss Humphrey (Mod840, 50 MHz) ultrabiomicroscope to evaluate the changes that Brimonidine, Apraclonidine, Latanoprost and Ibopamine cause in the anterior chamber and on the ciliary body of healthy subjects. The eyes of 60 volunteers, separated into 4 groups according to drug instilled, were studied and the parameters analyzed were: anterior chamber depth (ACD), pupillary diameter (PD), angle opening at 500 microns from the scleral spur (AOD500), trabecular iris angle (TIA) and iris thicknesses (ID1 and ID3). The study showed the miotic effect of Brimonidine (S) that was accompanied by an angle opening (S). Apraclonidine and Latanoprost caused no statistically significant changes in the angle or in the ciliary body. Ibopamine caused mydriasis (S). The UBM, therefore, showed itself to be useful also in the study of the mechanism of action of drugs on the angular structures and on the ciliary body.
Asunto(s)
Agonistas alfa-Adrenérgicos/farmacología , Cámara Anterior/efectos de los fármacos , Cuerpo Ciliar/efectos de los fármacos , Desoxiepinefrina/análogos & derivados , Midriáticos/farmacología , Prostaglandinas F Sintéticas/farmacología , Agonistas alfa-Adrenérgicos/administración & dosificación , Anciano , Cámara Anterior/diagnóstico por imagen , Tartrato de Brimonidina , Cuerpo Ciliar/diagnóstico por imagen , Clonidina/administración & dosificación , Clonidina/análogos & derivados , Clonidina/farmacología , Desoxiepinefrina/administración & dosificación , Desoxiepinefrina/farmacología , Femenino , Estudios de Seguimiento , Humanos , Presión Intraocular/efectos de los fármacos , Latanoprost , Masculino , Persona de Mediana Edad , Midriáticos/administración & dosificación , Soluciones Oftálmicas/administración & dosificación , Soluciones Oftálmicas/farmacología , Prostaglandinas F Sintéticas/administración & dosificación , Quinoxalinas/administración & dosificación , Quinoxalinas/farmacología , Valores de Referencia , UltrasonografíaRESUMEN
In cold-atom frequency standards based on the Ramsey double interaction method, the phase noise of the interrogating signal appears as a random "end-to-end phase difference", thereby introducing frequency noise in the loop. This phenomenon is analyzed in this paper in the Fourier frequency domain, using phase noise power spectral densities S(phi)(f). In continuously operated standards, the excess noise thus introduced is servoed out in the long term to become eventually smaller than the atomic shot noise, whereas in standards with pulsed operation the phase noise around even harmonics of the pulse rate is down-converted by aliasing to base band. This latter mechanism is referred to in the literature as Dick effect. In this paper, a model of the frequency control servo system is proposed, in which the input signal is the (known) local oscillator (LO) phase noise S(phi)(f) and the output signal is the (unknown) phase noise S(phi)(f) of the standard in closed loop operation. The level of excess white frequency noise added by aliasing on the stabilized LO through the Dick effect can be related analytically to the characteristics of the free LO phase noise. From this, the stability limitation (with slope tau(-1/2)) typical of the Dick effect can then be obtained by the usual conversion formulas based on the power law model.
RESUMEN
We report a case of anterior myocardial infarction which occurred in a young woman without history of cardio-vascular disease 10 days after she had given birth. Coronary arteriography performed 2 months later showed a pseudo-aneurysm of the anterior interventricular artery consecutive to spontaneous dissection of this vessel. The other coronary arteries were normal.
Asunto(s)
Disección Aórtica , Aneurisma Coronario , Trastornos Puerperales , Adulto , Femenino , Humanos , EmbarazoRESUMEN
The present study was performed to examine serum aldosterone and plasma renin activity variations in normal and toxaemic pregnancy. Blood samples were collected by 166 normal pregnant women and 196 toxaemic women. Results don't show important differences between normal and toxaemic pregnancies concerning either serum aldosterone or plasma renin activity.
Asunto(s)
Aldosterona/sangre , Preeclampsia/sangre , Embarazo , Renina/sangre , Femenino , HumanosAsunto(s)
Melanoma/diagnóstico , Radioisótopos de Fósforo , Ultrasonografía , Neoplasias de la Úvea/diagnóstico , Adulto , Anciano , Femenino , Humanos , Masculino , Melanoma/diagnóstico por imagen , Melanoma/patología , Melanoma/terapia , Persona de Mediana Edad , Pronóstico , Cintigrafía , Neoplasias de la Úvea/diagnóstico por imagen , Neoplasias de la Úvea/patología , Neoplasias de la Úvea/terapiaRESUMEN
The influence of aromatization of testosterone occurring in adipose tissue has been studied in castrated obese male rats. The treatment for 30 days with a subliminal dose (115 micrograms/kg per day) of testosterone propionate improved significantly the sexual performance of castrated obese male rats as compared to the nonobese controls. Untreated castrated obese animals did not show any enhancement of sexual behavior. Furthermore, obesity failed to improve sexual performance in intact male rats. Measurements of plasma levels of testosterone and 17 beta-estradiol showed an increase in aromatization of testosterone in obese rats. Present data suggest that adipose tissue can be considered an important site for aromatization of testosterone to 17 beta-estradiol, and that aromatization is involved in the activation of sexual behavior in castrated male rats.