Airborne ultrasonic application on hot air-drying of pork liver. Intensification of moisture transport and impact on protein solubility.

Nowadays, there is increasing interest in developing strategies for the efficient and sustainable use of animal by-products, such as pork liver. In order to stabilize the product, a prior dehydration stage may be required due to its high perishability. The water removal process of pork liver is energy costly and time consuming, which justifies its intensification using novel technologies. In this sense, the aim of this study was to assess the effect of the airborne application of power ultrasound on the hot air-drying of pork liver. For that purpose, drying experiments were carried out at 30, 40, 50, 60 and 70 °C on pork liver cylinders at 2 m·s-1 with (US) and without ultrasonic application (AIR). The drying process was modeled from the diffusion theory and, in the dried pork liver, the protein solubility was analyzed in order to determine the effect of drying on the protein quality. The ultrasound application increased the drying rate, shortening the drying time by up to 40% at 30 °C. The effect of power ultrasound at high temperatures (60 and 70 °C) was of lesser magnitude. Drying at 70 °C involved a noticeable reduction in the protein solubility for dried liver, while the impact of ultrasound application on the solubility was not significant (p > 0.05).

Ultrasound intensification of Ferrochelatase extraction from pork liver as a strategy to improve ZINC-protoporphyrin formation.

The enzyme Ferrochelatase (FeCH), which is naturally present in pork liver, catalyses the formation of Zinc-protoporphyrin (ZnPP), a natural pigment responsible for the typical color of dry-cured Italian Parma ham. The aim of this study was to evaluate the feasibility of using high power ultrasound in continuous and pulsed modes to intensify the extraction of the enzyme FeCH from pork liver. US application during FeCH extraction led to an improved enzymatic activity and further increase in the formation of ZnPP. The optimal condition tested was that of 1 min in continuous US application, in which time the enzymatic activity increased by 33.3 % compared to conventional extraction (30 min). Pulsed US application required 5 min treatments to observe a significant intensification effect. Therefore, ultrasound is a potentially feasible technique as it increases the catalytic activity of FeCH and saves time compared to the conventional extraction method.

Ultrasonic characterization of salt, moisture and texture modifications in dry-cured ham during post-salting.

For the first time, this study addresses the use of non-destructive ultrasound to monitor ham post-salting. For that purpose, the ultrasonic velocity (1 MHz) and the weight loss of hams were measured regularly every 2 days up to 8 weeks after salting. Additionally, for different post-salting times, internal salt and moisture content and hardness were measured at different locations from the ham surface. The experimental results reflected that the ultrasonic velocity increased as the ham weight decreased (26.1 m/s per kg), showing a satisfactory correlation between both variables (r = 0.95). The ultrasonic velocity was also correlated with the salt and moisture content. However, ham hardness remained fairly constant during post-salting, which confirmed that characteristic textural changes mainly occur during the salting and drying-maturation stages. Thus, the ultrasonic velocity could be a reliable parameter with which to monitor not only overall modifications in ham weight, but also internal changes of moisture and salt content during post-salting in a non-destructive way.

Effect of high pressure processing temperature on dry-cured hams with different textural characteristics.

High pressure processing is mainly used to eliminate pathogenic microorganisms and extend the shelf-life of dry-cured hams, but it also modifies its texture. These changes might be different depending on the initial textural characteristics. In this study, texture, colour and colour stability were evaluated after pressurization at 600 MPa during 6 min at 7 °C, 20 °C and 35 °C in samples with different textural characteristics (no pastiness, medium and high pastiness groups). HP treatments produced an increase of hardness (F0) and lightness (L*) values and a decrease of softness/pastiness (Y2 and Y90) and redness (a*) values at any processing temperatures. However, the increase of F0 and L* values was more pronounced in non-pasty samples. In samples with high pastiness and softness, HP processing at high temperature (35 °C) reduced the intensity of pastiness. However, texture of hams with non-pasty texture might be negatively affected. Therefore, the optimal temperature of HP processing depends on the textural characteristics of dry-cured hams.

Intensification of heat transfer during mild thermal treatment of dry-cured ham by using airborne ultrasound.

The application of power ultrasound (PuS) could be used as a novel technology with which to intensify thermal treatments using hot air. Mild thermal treatments have been applied to improve the soft texture of dry-cured ham caused by defective processing. In this regard, the aim of this study was to assess the kinetic intensification linked to the application of airborne PuS in the mild thermal treatment using hot air of dry-cured ham. For this purpose, vacuum packed cylindrical samples (2.52±0.11cm in diameter and 1.90±0.14cm in height) of dry-cured ham were heated using hot air at different temperatures (40, 45, 50°C) and air velocities (1, 2, 3, 4, 6m/s) with (22.3kHz, 50W) and without PuS application. Heat transfer was analyzed by considering that it was entirely controlled by conduction and the apparent thermal diffusivity was identified by fitting the model to the heating kinetics. The obtained results revealed that PuS application sped up the heat transfer, showing an increase in the apparent thermal diffusivity (up to 37%). The improvement in the apparent thermal diffusivity produced by PuS application was greater at high temperatures (50°C) but negligible at high air velocities (6m/s). Heating caused an increase in the hardness and elasticity of dry-cured ham, which would correct ham pastiness defects, while the influence of PuS on such textural parameters was negligible.

Optimized sound diffusers based on sonic crystals using a multiobjective evolutionary algorithm.

Sonic crystals have been demonstrated to be good candidates to substitute for conventional diffusers in order to overcome the need for extremely thick structures when low frequencies have to be scattered, however, their performance is limited to a narrow band. In this work, multiobjective evolutionary algorithms are used to extend the bandwidth to the whole low frequency range. The results show that diffusion can be significantly increased. Several cost functions are considered in the paper, on the one hand to illustrate the flexibility of the optimization and on the other hand to demonstrate the problems associated with the use of certain cost functions. A study of the robustness of the optimized diffusers is also presented, introducing a parameter that can help to choose among the best candidates. Finally, the advantages of the use of multiobjective optimization in comparison with conventional optimizations are discussed.

Impact of applied ultrasonic power on the low temperature drying of apple.

Low temperature drying (LTD) allows high-quality dried products to be obtained, preserving the nutritional properties of fresh foods better than conventional drying, but it is a time-consuming operation. Power ultrasound (US) could be used to intensify LTD, but it should be taken into account that process variables, such as the level of applied power, have an influence on the magnitude and extension of the ultrasonic effects. Therefore, the aim of this work was to assess the influence of the level of applied ultrasonic power on the LTD of apple, analyzing the drying kinetics and the quality of the dried product. For that purpose, apple (Malus domestica cv. Granny Smith) cubes (8.8mm side) were dried (2m/s) at two different temperatures (10 and -10°C), without and with (25, 50 and 75 W) US application. In the dried apple, the rehydration kinetics, hardness, total phenolic content, antioxidant capacity and microstructure were analyzed to evaluate the impact of the level of applied ultrasonic power. At both temperatures, 10 and -10°C, the higher the ultrasonic power level, the shorter the drying time; the maximum shortening of the drying time achieved was 80.3% (at -10°C and 75 W). The ultrasonic power level did not significantly (p<0.05) affect the quality parameters analyzed. Therefore, US could be considered a non-thermal method of intensifying the LTD of fruits, like apple, with only a mild impact on the quality of the dried product.

Non-destructive determination of fat content in green hams using ultrasound and X-rays.

This work addresses the use of ultrasound (US) and medical dual energy X-ray absorptiometry methods to predict the fat content in green pork hams. Ultrasonic velocity (υ) and X-ray absorption were measured in 78 green hams. An increase in the fat content involved an increase in υ and a decrease in the X-ray attenuation measured at 2°C. Models developed to predict the fat content from the ultrasonic velocity or X-ray parameters provided errors of 2.97% and 4.65%, respectively. The combination of both US and X-ray technologies did not improve prediction accuracy. These models allowed green hams to be classified into three levels of fatness, with 88.5% and 65.4% of the hams correctly classified when using models based on ultrasonic and X-ray parameters, respectively. Therefore, US and X-rays emerge as useful quality control technologies with which to estimate the fat content in green pork hams.

Ultrasonic assessment of textural changes in vacuum packaged sliced Iberian ham induced by high pressure treatment or cold storage.

Ultrasonic measurements were used to characterize the effect of high pressure treatment (HPT) (600 MPa/6 min) or cold storage (6°C/120 days) on the textural properties of vacuum packaged dry-cured ham. The ultrasonic velocity, textural properties and fat content were determined in the ham packages. The ultrasonic velocity was related to the ham hardness, which depends on the sample composition. HPT induced molecular alterations which resulted in an average increase in the hardness of lean tissue of 0.2N and one of 0.3N in that of fatty tissue. These textural changes give rise to a velocity increase (8m/s for lean and 17 m/s for fatty tissue). The cold storage of the Iberian ham also led to an increase in hardness (average 1.10 N) and ultrasonic velocity (average 70 m/s). Therefore, the non-destructive ultrasonic technique could be a reliable method with which to assess the textural changes induced by HPT or cold storage on packaged dry-cured ham.

[Improving the care of critical patient family members: Agreed on strategies]. / Mejorando el cuidado a los familiares del paciente crítico: estrategias consensuadas.

INTRODUCTION: Within the context of participatory action research (PAR), a 4-stage process was established with the general aim of promoting improvements in the care offered to families of patients in the Intensive Care Unit (ICU). The 4 stages consisted of a situational diagnosis, proposals for change, the design and implementation of the proposals, and an evaluation. This paper presents the first 2 stages. OBJECTIVES: To define the attention given to families of patients in the Intensive Care Unit. To reach a consensus on areas for action/intervention in the unit. MATERIALS AND METHOD: A qualitative methodology. DESIGN: PAR. Data-collection technique: 4 focus groups made up of 10 professionals, and consensus with support groups made up of 30 members. Content analysis was performed. The theoretical saturation point was reached. RESULTS: Two documents were drawn up: 1) A situational diagnosis, describing the current situation of the attention given to families and 2) 10 proposals for change, 5 of which were given priority. They were: a session to familiarize professionals with evidence concerning families of patients in the ICU and the handing out of informative leaflets, the improvement of (nurse-family and intra-team) informative procedures, more privacy for patients and a reduction in environmental noise, a training plan for professionals, and change in the visiting policy. CONCLUSION: By using consensus-based methodologies, strategies for change can be prioritized and designed, adapted to the context in which they will be applied.

Hole distribution in phononic crystals: design and optimization.

An exhaustive study has been made into the potential improvement in attenuation and focusing of phononic crystal arrays resulting from the deliberate creation of vacancies. Use is made of a stochastic search algorithm based on evolutionary algorithms called the epsilon variable multi-objective genetic algorithm which, in conjunction with the application of multiple scattering theory, enables the design of devices for effectively controlling sound waves. Several parameters are analyzed, including the symmetries used in the distribution of holes and the optimum number of holes. The validity and utility of the general rules obtained have been confirmed experimentally.

Ultrasonic drying of foodstuff in a fluidized bed: Parametric study.

The application of high power ultrasound for dehydration of porous materials may be very effective in processes in which heat-sensitive materials such as foodstuffs have to be treated. In fact, high-intensity ultrasonic vibrations are capable of increasing heat and mass transfer processes in materials. The application of ultrasonic energy can be made alone or in combination with other kind of energy such as hot-air. In this case, ultrasound helps in reducing temperature or treatment time. The aim of this work is to study the effect of air flow rate, ultrasonic power and mass loading on hot-air drying assisted by a new power ultrasonic system. The drying chamber is an aluminium vibrating cylinder, which is able to create a high intensity ultrasonic field in the gas medium. To that purpose the chamber is driven at its centre by a power ultrasonic vibrator at 21.8 kHz. Drying kinetics of carrot cubes and lemon peel cylinders were carried out at 40 degrees C for different air velocities, with and without ultrasound. The results show that the effect of ultrasound on drying rate is affected by air flow rate, ultrasonic power and mass loading. In fact, at high air velocities the acoustic field inside the chamber is disturbed and the effect of ultrasound on drying kinetics diminishes.

Intra-abdominal gastrointestinal tract injuries following blunt trauma: the experience of an Australian trauma centre.

AIMS: The aim of the study was to use the extensive experience of an Australian Level I trauma centre to develop guidelines for diagnosis and management of significant gastrointestinal tract injuries (GITIs). METHODS: This was a retrospective study of 74 patients admitted to Westmead Hospital between 1985 and 1996 who had sustained major gastrointestinal tract (GIT) injuries following blunt trauma. The patients were identified from the trauma unit database. Clinical information was retrieved from the database and augmented by a review of the medical records. RESULTS: Motor vehicle accidents were responsible for 55 (92%) admissions. Laparotomy was performed as a result of a positive diagnostic peritoneal lavage in 26 (35.1%) patients, abdominal signs in 20 (27%), diagnostic findings on computed tomography in 19 (25.7%), haemodynamic instability in eight (10.8%) and a positive contrast study in one (1.4%) patient. There was a total of 95 injuries: one gastric (1.1%), eight duodenal (8.4%), 64 small bowel (67.3%), two appendiceal (2.1%), 19 colonic (20%) and one rectal (1.1%). Thirty day mortality was 23% (17 patients). Seven (9.5%) patients died within 24h of injury, three (4.1%) of which were directly related to the GIT. Ten (13.5%) patients died within 2 weeks of admission, three (4.1%) of which were attributable to the GIT. Thirty day GIT morbidity was 29.7% (22 patients). The development of GIT morbidity was significantly related to a delay to laparotomy of more than 24h (P=0.036) and tachycardia on presentation (P=0.023). Associated injuries, injury severity scores (ISS) and age did not significantly impact on GITI related morbidity and mortality. DISCUSSION: Major GITIs are associated with a high mortality due to the severity and complexity of associated injuries. Morbidity from GITIs correlates to delays in diagnosis and management.

Refractive acoustic devices for airborne sound.

We show that a sonic crystal made of periodic distributions of rigid cylinders in air acts as a new material which allows the construction of refractive acoustic devices for airborne sound. It is demonstrated that, in the long-wave regime, the crystal has low impedance and the sound is transmitted at subsonic velocities. Here, the fabrication and characterization of a convergent lens are presented. Also, an example of a Fabry-Perot interferometer based on this crystal is analyzed. It is concluded that refractive devices based on sonic crystals behave in a manner similar to that of optical systems.

Quantitative analysis of herpesvirus sequences from normal tissue and fibropapillomas of marine turtles with real-time PCR.

Quantitative real-time PCR has been used to measure fibropapilloma-associated turtle herpesvirus (FPTHV) pol DNA loads in fibropapillomas, fibromas, and uninvolved tissues of green, loggerhead, and olive ridley turtles from Hawaii, Florida, Costa Rica, Australia, Mexico, and the West Indies. The viral DNA loads from tumors obtained from terminal animals were relatively homogeneous (range 2-20 copies/cell), whereas DNA copy numbers from biopsied tumors and skin of otherwise healthy turtles displayed a wide variation (range 0.001-170 copies/cell) and may reflect the stage of tumor development. FPTHV DNA loads in tumors were 2.5-4.5 logs higher than in uninvolved skin from the same animal regardless of geographic location, further implying a role for FPTHV in the etiology of fibropapillomatosis. Although FPTHV pol sequences amplified from tumors are highly related to each other, single signature amino acid substitutions distinguish the Australia/Hawaii, Mexico/Costa Rica, and Florida/Caribbean groups.

Reflectance properties of two-dimensional sonic band-gap crystals.

An analysis of the reflectance of sonic band-gap crystals consisting of square arrays of rigid cylinders in air is presented. The standing wave formed in front of the structures is studied both experimentally and theoretically. Experiments have been performed with a mobile robotized microphone that obtains pressure maps on the plane perpendicular to the axes of the cylinders. Enhancements of the standing wave ratio (SWR) are observed in frequency regions where attenuation bands appear in zero-order transmission experiments. Also, the SWR presents oscillations that can be related to the finite dimension of the structure (Fabry-Perot effect). Both features are well described by calculations based on a double-scattering approach.

Primary prevention of acute respiratory tract infections in children using a bacterial immunostimulant: a double-masked, placebo-controlled clinical trial.

BACKGROUND: Acute respiratory tract infections (ARTIs) are among the main causes of morbidity and mortality in children. The bacterial extract OM-85 BV has shown some protective effect for ARTIs in preschool children and a reduction in exacerbations of chronic bronchitis in adults. OBJECTIVES: This trial reports results of a double-masked, placebo-controlled, parallel-group clinical study that assessed the efficacy and tolerability of OM-85 BV in the prevention of ARTIs in school girls living in an orphanage. METHODS: Two hundred girls (age range, 6 to 13 years) living in an orphanage entered the trial. Participants were randomly allocated to receive either OM-85 BV or placebo for 10 consecutive days a month for 3 consecutive months. Patients were followed up for 6 months, including the administration period. The trial began in September 1996 and finished in March 1997. Primary end points were the type and number of infections. Secondary end points included when an infection occurred, time to clinical cure, severity of infection, absenteeism from school due to an ARTI, number of antibiotics or other drugs prescribed, and duration of concomitant drug treatment. RESULTS: During the trial, patients in the OM-85 BV group experienced 143 ARTIs (135 upper ARTIs and 8 otitis episodes) and patients in the placebo group experienced 299 ARTIs (273 upper ARTIs, 1 lower ARTI, and 25 otitis episodes). The median number of ARTIs was 1.0 (0.0, 3.0; 5th percentile, 95th percentile) in the OM-85 BV group compared with 3.0 (2.0, 4.0; 5th percentile, 95th percentile) in the placebo group. This difference was statistically significant (P < 0.001). Participants who received OM-85 BV also showed significantly better results (P < 0.001) than participants who received placebo in terms of median duration of illness, median number of missed school days due to an ARTI, median number of antibiotic and drug courses, and median duration of concomitant treatment. There were significant differences (P < 0.05) in severity of ARTIs during month 4 of the trial, with patients receiving OM-85 BV showing less severe ARTIs than patients receiving placebo and shorter mean time to clinical cure from the second month to the fourth month. No adverse events related to the trial medications were reported. CONCLUSIONS: OM-85 BV had a preventive effect on ARTIs in the school girls, with a reduction in the antibiotic requirements and the duration of ARTIs. Future studies are needed to further explore the role of OM-85 BV in the prevention of ARTIs.

[Giant fibroepithelial polyp of the ureter]. / Pólipo fibroepitelial gigante del uréter.

OBJECTIVE: To report a case of giant fibroepithelial polyp of the ureter and review the literature with special reference to the diagnosis and treatment of this benign condition. METHODS: A young male patient with a nonfunctioning left kidney caused by a giant fibroepithelial polyp of the ureter is presented. The diagnostic methods and treatment options are discussed. RESULTS: Following the diagnosis of obstructive uropathy with loss of left renal unit function, a left nephroureterectomy was performed which revealed a giant polypoid mass. CONCLUSION: Fibroepithelial polyp of the ureter is a benign condition that is difficult to diagnose with current endoscopic techniques. Endoscopy should be the first therapeutic option if loss of renal function is not irreversible.

Large two-dimensional sonic band gaps.

We show that absolute sonic band gaps produced by two-dimensional square and triangular lattices of rigid cylinders in air can be increased by reducing the structure symmetry. In the case of square lattices, symmetry reduction is achieved by a smaller diameter cylinder placed at the center of each unit cell. For triangular lattices the reduction is achieved by decreasing the diameter of the cylinder at the center of the hexagons in the lattice. Theoretical predictions are also demonstrated experimentally: starting from a honeycomb lattice (using cylinders of 4 cm of diameter size and 6.35 cm nearest-neighbor distance) we have studied the transition to a triangular symmetry by putting rods with increasing diameter (in the range 0.6-4 cm) at the center. The greatest enhancement of the attenuation strength observed in transmission experiments has been obtained in the high frequency region for diameter ratios in the range 0.1-0.3.