Superconducting NbC nanoparticles synthesized by laser ablation in a liquid.

Niobium carbide (NbC) is a high-field type II superconductor with a critical temperature () of 11.1 K, slightly exceeding that of pure Nb ( = 9 K). The reduction of NbC to the nanoparticle scale leads to significant changes in its critical field and/or the superconducting temperature.

Q-band 4-state phase shifter in planar technology: Circuit design and performance analysis.

A 30% bandwidth phase shifter with four phase states is designed to be integrated in a radio astronomy receiver. The circuit has two 90° out-of-phase microwave phase-shifting branches which are combined by Wilkinson power dividers. Each branch is composed of a 180° phase shifter and a band-pass filter.

The Thirty Gigahertz Instrument Receiver for the QUIJOTE Experiment: Preliminary Polarization Measurements and Systematic-Error Analysis.

This paper presents preliminary polarization measurements and systematic-error characterization of the Thirty Gigahertz Instrument receiver developed for the QUIJOTE experiment. The instrument has been designed to measure the polarization of Cosmic Microwave Background radiation from the sky, obtaining the Q, U, and I Stokes parameters of the incoming signal simultaneously. Two kinds of linearly polarized input signals have been used as excitations in the polarimeter measurement tests in the laboratory; these show consistent results in terms of the Stokes parameters obtained.

The thirty gigahertz instrument receiver for the Q-U-I Joint Tenerife experiment: concept and experimental results.

This paper presents the analysis, design, and characterization of the thirty gigahertz instrument receiver developed for the Q-U-I Joint Tenerife experiment. The receiver is aimed to obtain polarization data of the cosmic microwave background radiation from the sky, obtaining the Q, U, and I Stokes parameters of the incoming signal simultaneously. A comprehensive analysis of the theory behind the proposed receiver is presented for a linearly polarized input signal, and the functionality tests have demonstrated adequate results in terms of Stokes parameters, which validate the concept of the receiver based on electronic phase switching.

Design methodology and performance analysis of a wideband 90° phase switch for radiometer applications.

This paper presents the analysis, design, and characterization of a wideband 90° phase switch in Ka-band. The phase switch is based on two microstrip bandpass filters in which the commutation is performed by a novel single-pole double-throw (SPDT) switch. The analysis of π-network bandpass filters is provided, obtaining the phase difference and amplitude imbalance between filters and their scattering parameters; tested results show an average phase difference of 88.

Variables affecting BMI evolution at 2 and 5 years after vertical banded gastroplasty.

Background: Vertical banded gastroplasty (VBG) has been found to result in significant reduction in body mass index (BMI) during the first postoperative year. We investigated the impact of some intrinsic and extrinsic factors on long-term BMI evolution in morbidly obese patients who underwent VBG, with the aim of establishing a long-term weight-loss prognosis.

Methods: 67 consecutive morbidly obese patients who underwent VBG were followed for 2 years; of these, 34 were followed 3 more years, for a total follow-up of 5 years.

Application of the POSSUM system in bariatric surgery.

Background: The POSSUM system has been devised for physiologic and operative scoring. The scoring system produced assessment for morbidity and mortality rates, which did not significantly differ from observed rates. The authors have applied this system to bariatric surgery.

"No punch" technique of laparoscopic vertical banded gastroplasty for morbid obesity.

Background: This report describes the technical details and an initial evaluation of laparoscopic vertical gastroplasty modified for morbid obesity. After a surgical experience in 150 patients with open vertical banded gastroplasty (Mason's procedure), it was decided to perform a modified banded vertical gastroplasty.

Materials And Methods: Six patients were treated by this laparoscopic approach in 1997-1998.

Technical alternatives in laparoscopic distal gastric bypass for morbid obesity in a porcine model.

Background: Laparoscopic gastric bypass and vertical banded gastroplasty are two procedures used in the treatment of morbid obesity. The authors describe alternative techniques of laparoscopic distal gastric bypass as a modification of the Scopinaro procedure, which were used experimentally in a porcine model.

Methods: Five pigs were used.

Behavior of mitral allografts in the tricuspid position in the growing sheep model.

Background: On the basis of a previous experience in a chronic sheep model in which partial mitral allografts remained viable and properly functioning 12 months after operation, we assessed the results obtained by replacing the tricuspid valve with fresh antibiotic-preserved mitral allografts.

Methods: Twenty 3-month-old sheep with a mean weight of 23.7 +/- 2.

Mitral valve repair in rheumatic disease. The flexible solution.

Background: Mitral valve repair in rheumatic disease is technically more difficult, and there is little information on the long-term stability of this technique.

Methods And Results: From January 1975 to December 1990, 327 patients underwent mitral valve repair with the Duran flexible ring annuloplasty for rheumatic valve disease. Mean age was 45.

Partial replacement of mitral valve by homograft. An experimental study.

Satisfactory long-term clinical results with heart valves have renewed the interest in the use of mitral homografts, despite the technical difficulties with their surgical implantation. This report describes the behavior and viability of the partial mitral homograft in the ortotopic position in a chronic sheep model (n = 25). The 20 surviving animals were studied hemodynamically and were anesthetized and electively put to death 3, 6, 9, and 12 months after the operation.

Valve-related complications with the Hancock I porcine bioprosthesis. A twelve- to fourteen-year follow-up study.

Valve-related morbidity and mortality after heart valve replacement with the Hancock I porcine bioprosthesis has been retrospectively analyzed. From June 1974 through December 1976, 253 Hancock I bioprostheses (150 mitral and 103 aortic) were inserted in 220 selected patients who survived the operation and had follow-up until June 1989 (mean follow-up 13.5 years, with an accumulative follow-up of 2956.

Long-term evaluation of the Ionescu-Shiley pericardial xenograft bioprosthesis in the aortic position.

From August 1977 through October 1984, 241 patients underwent aortic valve replacement with the Ionescu-Shiley pericardial valve. There were 130 males and 11 females in this series with an average age of 50.8 years (range 15 to 78 years).

Long-term results of conservative repair of rheumatic aortic valve insufficiency.

From July 1974 to January 1986, 50 patients underwent conservative repair for rheumatic aortic valvular disease at our institution. Eleven were male and 39 female, with an average age of 39.5 years (range 17-57).

Intestinal and peripheral blood lymphocyte subpopulations in Crohn's disease.

Cellular immunity has been implicated in the pathogenesis of Crohn's disease. In the present work, we have studied T-lymphocytes subsets in peripheral blood and intestinal mucosa of eight patients with active disease, using monoclonal antibodies. Intraepithelial and lamina propia OKT-3 +ve cells were significantly lower than in peripheral blood (p less than 0.

Could alpha 1 antitrypsin deficiency have any role in the development of celiac sprue after gastric operations?

We report a 50-year-old woman with alpha 1 antitrypsin deficiency (PiSZ phenotype) who developed clinical features of malabsorption after vagotomy and pyloroplasty. The intestinal biopsy demonstrated total villous atrophy with hypertrophy of the crypts. After gluten withdrawal, digestive function and the appearance of the intestinal biopsy returned to normal.