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National audience; Cet article présente une évaluation de la fiabilité de la technologie SiGe SGB25 de la fonderie européenne IHP. Nous proposons ici une méthodologie permettant d'adresser les exigences liées aux contraintes spatiales. Pour cela des véhicules de test spécifiques ont été conçus. Ces véhicules de test seront ensuite introduits dans différentes files d'essais de vieillissement dont le but est de définir une aire de sécurité de fonctionnement en termes de contraintes électriques statiques et dynamiques. Nous attacherons une attention toute particulière à l'influence des modes de dégradation sur les performances en bruit.

International audience; The interest of surface acoustic wave devices (SAW) operating in radio-frequency range is their very high compactness, low losses and high quality factor. Thus, they are very interesting components for the stabilization of ultra-low noise on-board oscillators operating in direct bands. The need for working frequency beyond 3 GHz has lead SAW manufacturers to develop multilayer diamond-based waveguides providing higher phase velocity than conventional single-crystal materials, typically ranging from 7 to 12 km.s-1 for elliptically polarized waves. The very problem in this approach is the excitation and detection of acoustic waves requiring a high quality piezoelectric layer of less than one micrometer thick with physical properties as close as possible to the tabulated ones. An ultimate control of the film thickness and roughness is required to control dispersion and diffusion losses. In this work, we investigated a structure based on Nano-Crystalline Diamond (NCD). The waves are launched and detected using a Zinc Oxide film deposited atop the diamond layer, yielding notable dispersive properties of the device. In this way, technological developments have been achieved (NCD growth, piezoelectric layer deposition, e-beam and optical lithography) to build SAW devices taking advantage of NCD films to try and benefit from their suspected low acoustic damping. Results show the possibility of developing devices operating between 2 and 3 GHz at minimum, having losses lower than 10 dB. At last, devices whose dimensions are compatible with conventional lithography processes, show resonances at more than 4 GHz with less than 8 dB of insertion loss, what is, at the knowledge of the authors, the best experimental result for such devices. To compare with previous results, a device operating near 3 GHz has been used to stabilize an oscillator. Short term stability has been measured at 10-8 s-1 and a phase noise floor was observed at -170 dB at 3 MHz from the carrier. Although not yet meeting the expected requirements, these results show the impact of loss reduction and general device improvement and allow for preparing future work near 5 GHz.

fluoroscopic equipment. There are several limitations to the intracardiac 24 mensional ultrasound catheter system used in the present study. First, in the absence of 3-dimensional capability, the entire transseptal catheter/needle profile cannot be visualized. Therefore, manipulation of the catheter/needle and the transseptal puncture must still be done under fluoroscopic view. Second, the 10 MHz transducer has a limited depth penetration. Thus, the entire interatrial septum may not be visualized in some patients (Figure 1B). However, the ultrasound system provides adequate imaging of needle/catheter contact point at the septum. Therefore, puncture of unwanted structures can be avoided. Finally, the present over-the-wire ultrasound catheter has,a large ‘1OFr profile. With technical advancements and refinements, some of the limitations may be overcome in the future. For example, it may be possible to develop a lower frequency (e.g., 7.5 MHz) transducer catheter for better depth penetration and to reduce the ultrasound catheter profile by eliminating the over-the-wire design. In conclusion, our study indicates that intracardiac echocardiography facilitates safe transseptal catheterization by supplementing a single frontal fluoroscopy.

Seven human ocular melanoma cell lines were established in vitro and 3 of these, GU-4, LLN-40 and its subline C17-11, were characterized. Mice were immunized with these ocular melanoma cell lines, and 2 hybridomas producing monoclonal IgG1antibodies (MAb) were produced. MAb 2/10SN recognizes a 44-kDa monomeric protein, whereas MAb 10/12SN reacts with an 83/65-kDa heterodimeric protein. These melanoma-associated antigens (MAA) are detected at high concentrations in the cytoplasm of ocular melanoma cells. However, cell-surface labelling techniques suggest that these MAA are also associated with the cell-surface membrane. These 2 ocular MAA are also expressed by several skin melanoma cell lines. Immunohistochemical studies have localized these antigens to ocular and skin melanomas, to sweat ducts and basal squamous cells in normal skin, with limited expression in several other normal tissues and some carcinomas. Biodistribution studies in nude mice with human ocular melanomas have demonstrated good localization of 125I-labeled MAb 2/10SN at the tumor sites. Therefore, these 2 MAbs, 2/10SN and 10/12SN, recognize MAA which appear to be unique and may prove useful for imaging purposes. © 1992 Wifey-Liss, Inc.

The phase noise performance of two different microwave analog frequency dividers is characterized and compared with the values obtained using simple theories of noise in injection-locked systems. The direct measurement of the divider noise with a low phase noise synthesizer is not accurate enough, and the residual noise technique is used. The noise levels observed using this technique, between -120 and -155 dBc/Hz at a 10 kHz offset frequency, demonstrate that this divider noise is much lower than the phase noise of most microwave free running oscillators, even if this noise is still high with respect to the residual noise of amplifiers realized with the same active devices. The down conversion of microwave sources up to 40 GHz, is proposed as an application example.

A new analog frequency divider configuration using a resistive field-effect transistor (FET) mixer with a series feedback is proposed. With this configuration, a large synchronization bandwidth of almost 30% has been achieved using an original CAD technique. This bandwidth has been effectively measured on a Ku-band monolithic microwave integrated circuit (MMIC) circuit together with an ultra-low power consumption. Moreover, the processed circuit using a standard 0.2-/spl mu/m PHEMT technology (Philips-PML) is very compact (1.5 mm/sup 2/).

** In order to go further in the path to a space level compliant fully integrated Local Oscillator (LO), this study proposes a solution to the integration of one of the key circuits of the nowadays best performing Phase Locked Loop (PLL) topology : the Sampling Phase Detectors (SPD). After introducing Phase Locked Loop mostly used topologies, the authors focus on phase transfer functions in order to enlighten Sampling Phase Detector advantage over Phase Frequency Comparator as for low phase noise applications. Then Sampling Phase Detector general mode of operation is described to clearly state what must be taken into account to ensure its good performance. The usual hybrid topology is presented and its unapplicability to straight forward integration is discussed. Thus a new Sampling Phase Detector MMIC topology is introduced and its measured characteristics are presented. Eventually, new developments are discussed and results are commented to verify their compliance to expectation.

A new sampling phase detector monolithic microwave integrated circuit (MMIC) using a standard 0.18-/spl mu/m GaAs technology has been designed and tested. The authors emphasize that commutation time has to be taken into account rather than pulse duration, as done in previous presented works. Thus, the new SPD design concept eases command-signal generation. It also solves the tradeoff between phase detection and RF signal input-to-output isolation through the use of a double sampler topology and a proper command-signal generation. It has been designed taking care of space level specifications and environment. Phase detection level above 2 V/sub pp/ and operating frequencies up to 20 GHz have been measured, although higher frequency operation can be expected.

The phase noise performance of two different microwave analog frequency dividers is characterized and compared to the values obtained using simple theories of noise in injection locked systems. The direct measurement of the dividers noise with a low phase noise synthesizer being not enough accurate, the residual noise technique is used. The noise levels observed by this technique, between -120 dBc/Hz and -155 dBc/Hz at 10 kHz offset frequency, demonstrate that this dividers noise is much lower than the phase noise of most microwave free running oscillators, even if this noise is still high with respect to the residual noise of amplifiers realized with the same active devices. An application is proposed to the down conversion of microwave sources up to 40 GHz.

A contribution to the design of monolithic analog frequency dividers based on pseudomorphic high electron mobility transistors at microwave frequencies is reported. The different existing circuits are first described according to a new classification considering frequency division principles. Afterwards, an analytical approach based on simplified models is developed to lighten frequency division mechanism. Then a general methodological approach based on CAD techniques is studied through different analysis methods. Finally, the "open loop" method is rather chosen. However, some kind of chaotical bifurcation processes have been observed while using this method. A presented complementary study allow us to verify that they do not imply devices (physical) instability. A next part is dedicated to monolithic circuits design. Following some general considerations about the applied technology, a general design methodology and its direct application to the design of several frequency dividers are reported. Two of these circuits have been integrated The second one is based on a topology which makes use of a cold transistor as main element and features almost 30 % bandwidth. Experimental results are thus compared to the simulation and to previously published results. Eventually, a last part is dedicated to the phase noise in frequency dividers.; Ce travail est une contribution à la conception de diviseurs de fréquence analogiques réalisés en technologie monolithique à base de transistors pseudomorphiques à haute mobilité électronique aux fréquences micro-ondes. Après avoir décrit les divers circuits existants en choisissant une classification originale selon les différents principes régissant la division de fréquence, nous développons une approche analytique basée sur des modèles simplifiés afin de trouver les paramètres essentiels du phénomène. Nous expérimentons également diverses méthodes d'analyse sur calculateur avec pour objectif le développement d'une approche méthodologique générale. Finalement, la méthode dite "de la boucle ouverte" est choisie pour la conception de circuits. Lors de son utilisation, il est à noter que des processus proches de cascades de bifurcations chaotiques sont observés. Une étude complémentaire présentée permet de vérifier qu'ils ne sont pas directement liés à la stabilité (physique) du dispositif. Ces travaux de modélisation sont pour la suite appliqués à la conception de deux diviseurs en technologie monolithique. Une large bande de synchronisation d'environ 30 % a été obtenue avec une topologie originale utilisant un transistor non polarisé sur le drain. Les résultats expérimentaux sont ensuite comparés aux simulations effectuées précédemment ainsi qu'aux performances déjà publiées sur des circuits de ce type. Enfin, une dernière partie est consacrée au bruit de phase dans les diviseurs de fréquences.

OBJECTIVE: To evaluate the value of biliary carcino-embryonic antigen (CEA) in the differential diagnosis of malignant and benign hepatopancreatobiliary disease. PATIENTS: One hundred patients were prospectively studied. Benign diseases were present in 39% of the patients while 61% had malignant diseases. METHODS: Samples of serum were taken from all patients just before endoscopic retrograde cholangiopancreatography (ERCP) and samples of biliary CEA were obtained during ERCP. RESULTS: The sensitivity of serum CEA and carbohydrate antigen 19-9 (CA 19-9) in detecting malignancy were 50% and 92%, respectively, while the respective specificities were 95% and 72%. The mean biliary CEA level of the benign group was significantly different from that of the malignant group (35.7 +/- 8.7 ng/ml vs 268 +/- 85.5 ng/ml), but there was considerable overlap between the two groups. With a cut-off level of 20 ng/ml, the sensitivity and specificity were 84% and 64% respectively. The mean bilirubinaemia value was significantly higher in malignant disease than in benign disease (57.4 +/- 13.9 mumol/l vs 235 +/- 19.8 mumol/l). Multidimensional analysis indicated that only bilirubinaemia (P < 109-3)) was independently predictive of malignant disease. CONCLUSION: Biliary CEA assessment seems useless in distinguished between benign and malignant causes of cholestasis.

In order to detect and quantify intrapulmonary shunts in children with liver disease, a radionuclide method was developed and evaluated in such a population.We studied 135 children in whom the severity of liver disease, in most cases, justified consideration of liver transplantation. Patients were separated into two groups according to their resting PaO2 values under room air: 109 children were normoxic and 26 were hypoxic. A radionuclide scan was performed immediately after intravenous injection of human albumin macroaggregates. Activity of the lungs (L) and brain (B) was counted. A shunt index (SI) was calculated as SI = 100.B/L. We compared this index with blood gases and clinical follow-up.In the normoxic group, SI was 0.43 +/- 0.30 (mean +/- s.d.); none of the 102 children with SI1 developed hypoxemia during their follow-up. Two of the six children with SI1 developed subsequent hypoxemia. In the hypoxic group, the nine children with SI1 did not aggravate their hypoxemia during follow-up. The 17 hypoxic children with SI1 later developed severe hypoxemia.Scintigraphy with intravenous human albumin macroaggregates is more accurate than measuring arterial blood gases to detect IPS in children with cirrhosis.

Technetium 99m cardiac scintigraphy as practiced at present for diagnosing amyloisodid only provides a visual semi-quantitative assessment of uptake of the isotope. To improve the diagnostic accuracy of the method, the authors evaluated prospectively a personal technique of scintigraphy quantification based on early images obtained at the 20th minute in 15 patients with neuropathic amyloidosis. Doppler echocardiographic studies indicated that 9 patients had cardiac involvement whilst 6 were free of cardiac amyloidosis. The index of isotopic uptake (ratio of cardiac/abdominal uptake) was 0.44 to 1.58 in the first group and 0.09 to 0.31 in the second group. The correlation between the scintigraphic index and interventricular septal or posterior wall thickness measured by echocardiography was poor. These results obtained in 15 patients with neuropathic amyloidosis suggest that the scintigraphic index measured at the 20th minute is discriminatory and allows identification of those patients with cardiac involvement. On the other hand, the correlations with echocardiographic wall thickness are poor. Technetium 99m cardiac scintigraphy with this technique of quantification is a useful tool for diagnosing cardiac amyloidosis, especially when echocardiography is difficult to interpret.

Der Professor Etienne Barral (1860-1938). Organiker, Biologe, Toxikologe, Mineraloge, Verfasser zahlreicher Abrissen und anderer wissenschaftlichen Arbeiten, ist É. Borel, Doktor der Pharmazie und der Medizin, besonders durch die Entdeckung des « glykolytischen Fermentes » (1890-1891) - welche in ihm ein Vorläufer der Isolierung des Insulins zu erkennen gibt - bekannt geworden, sowie durch die Erfindung des sogenannten « anneau de Barral » Reagens., Professor Etienne Barral (1860-1938). Specialist in organic chemistry, biologist, toxicologist, mineralogist, author of numerous articles and other scientific works, É. Barral, doctor of pharmacy and of medicine, was known principally for his discovery of « glycolitic ferment » (1890-18891) which made him a forerunner in the isolation of insulin, and for his invention of the reagent called « Barral's ring »., Desgrez Pierre. Le Professeur Etienne Barral (1860-1938). In: Revue d'histoire de la pharmacie, 80ᵉ année, n°294, 1992. pp. 323-329.

Biliary pain without obvious biliary obstruction is common in postcholecystectomy patients. We studied 20 symptomatic patients with episodes of biliary-type pain after cholecystectomy (all having undergone endoscopic retrograde cholangiography), and in 18 asymptomatic postcholecystectomy controls. We performed quantitative hepatobiliary radionuclide analysis with dimethyl-imidodiacetic acid. From a series of 90 dynamic images at 1-min intervals using a gamma camera coupled to a computer, time-activity curves were produced in regions of interest in the liver, intrahepatic biliary tree, common duct, and heart, from which quantitative biliary excretion indexes were obtained. The results demonstrate a biliary kinetic dysfunction in patients with postcholecystectomy pain without morphological abnormalities.

A case of bifid ureter with a blind branch exhibiting no parenchymal connections is reported. Diagnosis was established by excretory urography. Less than twenty cases diagnosed in this way have been reported previously, the embryogenesis of the normal and bifid ureter is reviewed. Symptoms, which are inconsistently present, are described. Excision of the blind branch is required and should be accompanied with antireflux reimplantation of the normal ureter if called for.

Despite the progress in conventional medical imaging it retains certain limitations particularly in two areas: 1) the detection of prostatic cancer: the specificity and sensitivity of transrectal ultrasonography are too poor to justify the use of this modality for screening or for diagnosis. 2) Small renal tumours, which are detected increasingly frequently on ultrasound examinations. Computed tomography is the most reliable examination for determining the benign or malignant nature of the lesion. The other modalities are disappointing and an excessive repetition of medical imaging should be avoided.

Since 1980, in addition to internal urethrotomy, the authors have used urethrotomy combined with endoscopic resection of the stricture. This method consists of a classical first stage of section of the stricture, but only at 11 o'clock and at 1 o'clock to leave a rail of midline fibrosis. The second stage consists of resection of this rail. The value of this approach consists of more effective excision of the fibro-inflammatory callus. Thirty-four patients treated by this method have a follow-up exceeding 5 years. This series was compared with a series of patients treated by internal urethrotomy alone (39 patients with a follow-up greater than 5 years). Very good results were obtained in 55% of cases versus 28% with internal urethrotomy alone. Poor results were obtained in 32% of cases versus 43%. Internal urethrotomy therefore appears to be more rapidly and more completely effective.