Observation of Shell Structure, Electronic Screening, and Energetic Limiting in Sparks.

We study the formation of micron-sized spark discharges in high-pressure xenon on the nanosecond time scale. The spark's energy per length is measured through the expansion dynamics of the generated shock wave, and is observed to scale linearly with the spark radius. At the same time, the surface temperature of the spark channel remains constant. Together, these observations allow us to conclude that the spark channel, up to 40 µm in overall radius, is actually an energetically hollow shell about 20 µm thick. Further, the energy per nucleus in the shell is about 15 eV, independent of size and density. To reconcile these findings with the opacity to visible light, we appeal to collective screening processes that dramatically lower the effective ionization potential, allowing a much higher electron density than is otherwise expected. Thus, nanosecond measurements of sparks provide access to the thermodynamics and kinetics of strongly correlated plasmas.

Collision time measurements in a sonoluminescing microplasma with a large plasma parameter.

The plasma which forms inside of a micron-sized sonoluminescing bubble in water for under a nanosecond has been probed with 3 ns long laser pulses. A comparison of the response to 532 and 1064 nm light indicates that the plasma number density is about 2×10(21) cm(-3) and that transport properties are dominated by strong screening and correlation effects. The spherical shape, well-defined atomic density, and blackbody temperature make the sonoluminescing plasma a test bed for theories of strongly coupled plasmas. The plasma in this experiment distinguishes between competing theories of strong, intermediate, and weak effective screening.

Blackbody emission from laser breakdown in high-pressure gases.

Laser induced breakdown of pressurized gases is used to generate plasmas under conditions where the atomic density and temperature are similar to those found in sonoluminescing bubbles. Calibrated streak spectroscopy reveals that a blackbody persists well after the exciting femtosecond laser pulse has turned off. Deviation from Saha's equation of state and an accompanying large reduction in ionization potential are observed at unexpectedly low atomic densities-in parallel with sonoluminescence. In laser breakdown, energy input proceeds via excitation of electrons whereas in sonoluminescence it is initiated via the atoms. The similar responses indicate that these systems are revealing the thermodynamics and transport of a strongly coupled plasma.

Energy balance for a sonoluminescence bubble yields a measure of ionization potential lowering.

Application of energy conservation between input sound and the microplasma which forms at the moment of sonoluminescence places bounds on the process, whereby the gas is ionized. Detailed pulsed Mie scattering measurements of the radius versus time for a xenon bubble in sulfuric acid provide a complete characterization of the hydrodynamics and minimum radius. For a range of emission intensities, the blackbody spectrum emitted during collapse matches the minimum bubble radius, implying opaque conditions are attained. This requires a degree of ionization >36%. Analysis reveals only 2.1±0.6 eV/atom of energy available during light emission. In order to unbind enough charge, collective processes must therefore reduce the ionization potential by at least 75%. We interpret this as evidence that a phase transition to a highly ionized plasma is occurring during sonoluminescence.

New cases of accessory and cavitated uterine masses (ACUM): a significant cause of severe dysmenorrhea and recurrent pelvic pain in young women.

BACKGROUND: To raise awareness about the accessory and cavitated uterine masses (ACUM) with functional endometrium as a different entity from adult adenomyosis and to highlight the importance of a correct diagnosis, we studied four new cases of ACUM and 15 cases reported as juvenile cystic adenomyoma (JCA) by reviewing the literature from the last year. This entity is problematic because of a broad differential diagnosis, including rudimentary and cavitated uterine horns; and is generally underdiagnosed, being more frequent than previously thought. METHODS: We report four cases of young women who underwent surgery in our hospital from January to July 2011 after presenting with an ACUM. We also reviewed and tabulated the cases from literature beginning in 2010. Main outcome measures were diagnostic tools, surgical and histopathological findings and improvement of symptoms. RESULTS: The addition of the four cases reported here to the 15 published as JCA raises the total number of cases of ACUMs to 19, which is more than all of the cases reported prior to 2010. In our cases, it is interesting to highlight that one of them also had an adjacent accessory rudimentary tube and another had two ACUMs at the same location. All patients suffered from severe dysmenorrhea and pelvic pain and were young women. Suspicion, transvaginal ultrasound and magnetic resonance image were found to be the best diagnostic tools. Most of the cases were treated by laparoscopic tumorectomy. CONCLUSIONS: ACUMs are generally underdiagnosed and often reported as JCAs but they are not adenomyosis. Early surgical treatment involving the laparoscopic or laparotomic removal of the mass could prevent the usual prolonged suffering of these young women. In our opinion, this entity is a new variety of Müllerian anomaly.

Syndromic clubfoot beyond arthrogryposis and myelomeningocele: orthopedic treatment with Ponseti method. / Pie zambo sindrómico más allá de la artrogriposis y el mielomeningocele: tratamiento ortopédico con el método de Ponseti.

INTRODUCTION: Talipes equinovarus or clubfoot is a congenital deformity of the foot with bone, muscle, and tendon involvement. It's one of the most frequent foot malformations in pediatric orthopedics. Although generally idiopathic, it may have a syndromic cause and be associated with musculoskeletal, neurological, or connective tissue conditions. The treatment of choice in idiopathic clubfoot is the Ponseti method based on manipulation and fixation with serial casts that seek progressive correction of the deformity. The Ponseti method effectiveness has been demonstrated in arthrogryposis and myelomeningocele clubfoot. There are few clinical studies demonstrating the efficacy of this therapeutic option in patients with syndromic clubfoot. MATERIAL AND METHODS: Retrospective study with 6 patients (9 feet) with syndromic clubfoot treated in a tertiary center with the Ponseti method with a minimum follow up of two years (2-18). The results were evaluated with the Pirani classification, assessing clubfoot severity before and after treatment. RESULTS: Of the six patients treated were used an average of 6.5 casts. The Pirani scale obtained a mean score of 5.2 before treatment, with a decrease to 1.27 after treatment, with a mean improvement of 3.93 points. In more than half of the cases it was necessary to lengthen the Achilles tendon to correct the equine deformity. In addition, an ankle-foot orthosis was used to reduce recurrences in patients with dysmetria or psychomotor retardation. The most frequently observed residual deformity was the adduct. A patient relapsed twice. CONCLUSIONS: The Ponseti method obtains effective results in the correction of syndromic clubfoot, although it requires a greater number of corrective casts than other pediatric foot pathologies.

[Mixed hepatopathy due to parenteral gold salts]. / Hepatopatía mixta por sales de oro vía parenteral.

A case of a patient with rheumatoid arthritis (RA) of long evolution associated to dry syndrome, who developed a dissociated cholestasis after parenteral administration of gold salts, is suppression of gold salts. We comment on the clinical, biochemical, and histological features of intrahepatic cholestasis related to gold salts, as well as the evolution and the necessary criteria in order to make the diagnosis. We highlight the normal level of bilirubin, comparing it to that described in the literature.

[Prevalence of HIV antibody carriers in patients assisted in the recovery room]. / Prevalencia de portadores de anticuerpos VIH en pacientes asistidos en reanimación.

A study has been performed on 200 patients at the Recovery Department of our hospital during 1987. This study was carried out in order to determine patients with human immunodeficiency virus (HIV) antibody. This group was randomized and consisted of 154 men and 46 women, with an average age of 35.6 +/- 3.9, a total weight of 68 +/- 6 kg and a height of 1.69 +/- 0.2 m. The day entered at the Recovery Department we assessed the following parameters: a) addiction to drugs by parenteral way; b) bleeding; c) invasive procedures; d) etiology, and e) blood samples were drawn for plasma antibody to HIV. We detected five patients (2.5%) with antibody anti-HIV and all of these patients were male and they were aged in 20-39 years old. We noticed a close relation between addiction to drugs and HIV (p less than 0.001), nevertheless no relation has been found between invasive procedures, bleeding, etiology and antibody to HIV. We conclude that the number of patients that we detected with antibody from the HIV is similar to those found by other studies that has been carried out in emergency situation, but greater than those found in the screening of the general population.

[Application of continuous positive pressure to the uppermost lung in patients ventilated through a single lung]. / Aplicación de presión positiva continua al pulmón proclive en pacientes ventilados a un solo pulmón.

We have studied the oxygenation process in a series of 20 patients who underwent thoracic surgery and were ventilated through a single lung. There were 19 men and one woman with a mean age (+/- SD) of 63 +/- 10.5 years, a mean height of 166 +/- 37.9 cm and a mean weight of 67 +/- 14.1 kg. Premedication and anesthesia were comparable among all patients. Endotracheal intubation was performed with a double lumen Robersthaw cannula. After anesthetic induction the radial and pulmonary arteries were catheterized to obtain samples for gasometric investigation in arterial and venous mixed blood before and after exclusion of one lung with continuous positive pressure (CPAP). Gasometric analysis was also performed during the immediate postoperative period. All patients were ventilated with 100% oxygen concentration 20 min before blood sampling in order to remove the alveolar nitrogen. During single lung ventilation and during application of CPAP (5 cm H20) to the upright sided lung we observed a 50% increase in arterial p02 (Pa02) (p less than 0.001) without any change in mean alveolar p02 (PA02). There was also a 17% decrease in alveolo-arterial oxygen difference (D[A-a]02) (p less than 0.001) and a 16.6% reduction in the intrapulmonary shunt (Qs/Qt) (p less than 0.001). Improvement of oxygenation was attributed to a beneficial effect of CPAP applied to the upright sided lung while intermittent positive pressure was maintained in the recumbent lung.

[Acute respiratory failure in chronic obstructive lung disease. Effective weaning and excess base]. / Fallo respiratorio agudo en la enfermedad pulmonar obstructiva crónica. Desconexión eficaz y exceso de base.

To establish whether the weaning from assisted mechanical ventilation (AMV) should be accompanied by continuous respiratory support (synchronized intermittent mandatory ventilation [SIMV]) or discontinuous support (O2 in T) in patients affected by chronic obstructive lung disease (COLD) who are recovering from acute respiratory failure (ARF), and also to identify any possible predictive value of gasometric measurements. Sixteen patients with COLD and ARF were studied prospectively during their stay in the intensive care unit. Ten had acute bronchitis, 3 had left ventricular failure and 2 had pneumonia. In 1 case the etiology was unknown. The following protocol was used for the first attempt at weaning: 1) SIMV for 30 min, 2) return to rest period with AMV for 2 hours, 3) O2 in T-tube for 30 min. After 30 min both SIMV and O2 in T had produced a rise in PaCO2 to 55.1 and 54.6 mmHg, respectively (p < 0.001), with a subsequent lowering of pH to 7.32 and 7.36 (p < 0.001). When weaning was well tolerated, pH decreased significantly due to an increase in PaCO2 with both techniques, while base excess (BE) remained stable. Values of pH also decreased significantly when weaning was poorly tolerated, and the fall was greater with SIMV; increases in PaCO2 were similar, but decreases in BE were significant. When pH is kept within normal range by a high BE, the withdrawal of AMV, accompanied by either support system, is usually well-tolerated.

Genetic syndromes mimic congenital infections.

Genetic syndromes that mimic congenital infection are important to recognize because of the associated risk of recurrence. We describe two brothers born to consanguineous parents with clinical features suggestive of intrauterine infection but with negative serologic investigations. Our observations suggest that Aicardi-Goutieres syndrome (AGS) and pseudo-TORCH syndrome likely represent the same disorder.

Modifications of tissular oxygenation and systemic hemodynamics after the correction of hypocapnia induced by mechanical ventilation.

The modifications of systemic hemodynamics, oxygen transport and tissular oxygenation in mechanically-ventilated critical ARF (acute respiratory failure) patients, after the correction of its hypocapnia by addition of dead space (VD) are determined. The prospective and randomized study was carried out in a multidisciplinary ICU. Fifteen ARF patients were studied within the first 48 hours of evolution. All the patients were intubated and mechanically ventilated. Three stages were delimited: I) 30 min after the beginning of anesthesia; II) 30 min after adding 30 cm of VD; III) 30 min after replacing the previous VD with a VD of 60 cm. Similar steady states had been reached when the measurements were taken. Ventilation parameters and FiO2 were kept stable. In stage I the patients presented a pure respiratory alkalosis and, with respect to hemodynamics, a hyperdynamic situation. In stage II the acid-base balance was normalized with a continuation of the hyperdynamic situation and an increase in mixed venous oxygen tension and saturation (PvO2 and SvO2) (p < 0.001). Stage III was characterized by a pure hypercapnic acidosis and an increase in capillary wedge pressure (CWP) (p < 0.05), right atrial pressure (RAP) (p < 0.001) and cardiac output (Qt) (p < 0.001); simultaneously, the systemic vascular resistances (SVR) decreased (p < 0.01), the PvO2, SvO2 and oxygen delivery (DO2) increased (p < 0.001); oxygen utilization coefficient (OUC) decreased (p < 0.01). The results suggest that the variations in PvO2 and SvO2 are a direct consequence of the modifications in blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)