Data reduction for spatially resolved reflectance anisotropy spectrometer.

We show that in spatially resolved reflectance anisotropy (RA) spectrometers, off-axis optical rays introduce a spurious signal component that cannot be addressed by optical alignment. Such a component is associated with the difference between the reflectivities s and p of the sample and depends, in a complex manner, on the incidence position of the incident light on the surface of the sample. We report a data-reduction procedure to easily identify and remove spurious RA signals associated with the off-axis optical rays, based on the singular value decomposition analysis of spatially resolved RA spectra. We validated this approach by developing a spatially resolved RA spectrometer based on an 8 × 8 multi-anode photomultiplier (PMT). The PMT allowed the use of phase-sensitive detection techniques to enhance the signal-to-noise ratio, which is essential for the evaluation of the proposed data reduction procedure.

Properties of reformulated hot dog sausage without added nitrites during chilled storage.

The aim of this study was to assess the effect of a complete nitrite replacement strategy using celery, carmine, sodium lactate and orange dietary fibre combined with vitamins C and E, on the quality characteristics (technological, sensorial and safety properties) of hot dog sausages (five samples) during chilled storage (2 ± 1℃ 60 days). Nitrite replacers (combined with vitamins C and E) presented antioxidant activity, reducing lipid oxidation in reformulated samples. At the end of storage redness (a*) was similar in the control sample (with added nitrite) and in the sample without added nitrite. Sensory evaluation detected no significant difference between samples with and without added nitrite. All the reformulated samples were judged acceptable by the panellists. At the end of storage, the control sample contained more than four times as much residual nitrite as the reformulated samples. Growth of presumptive Clostridium perfringens was not observed in any of the samples. Samples without added nitrite had longer shelf-lives than control sausage. Samples containing 0.1% vitamin C registered the lowest microbiological levels. This strategy could be a good alternative to reduce and/or eliminate added nitrite in hot dog sausages.

Nitrite-free Asian hot dog sausages reformulated with nitrite replacers.

This research deals with the application of a global strategy designed to produce a nitrite-free Asian hot dog. Different ingredients such as annatto, cochineal, orange dietary fibre, vitamins E and C, lactate and celery were combined in order to study the appearance (colour), lipid oxidation stability and microbial stability of the nitrite-free formulations. The control sample contained much more (P < 0.05) residual nitrite (88.7 mg/kg) than the samples without added nitrite (23-24 mg/kg). Generally, no formulation-dependent variations were observed in fat and water binding properties. Control sample had the highest L* and a* values, while the product with annatto (RA) had the lowest a* values. Lipid oxidation levels were similar irrespective of formulation. The hot dog reformulated with cochineal (RC) scored higher for overall acceptability than RA, mainly due to its colour.

Konjac gel as pork backfat replacer in dry fermented sausages: processing and quality characteristics.

The effect of replacing animal fat (0%, 50% and 80% of pork backfat) by an equal proportion of konjac gel, on processing and quality characteristics of reduced and low-fat dry fermented sausage was studied. Weight loss, pH, and water activity of the sausage were affected (P<0.05) by fat reduction and processing time. Low lipid oxidation levels were observed during processing time irrespective of the dry sausage formulation. The fat content for normal-fat (NF), reduced-fat (RF) and low-fat (LF) sausages was 29.96%, 19.69% and 13.79%, respectively. This means an energy reduction of about 14.8% for RF and 24.5% for LF. As the fat content decreases there is an increase (P<0.05) in hardness and chewiness and a decrease (P<0.05) in cohesiveness. No differences were appreciated (P>0.05) in the presence of microorganisms as a result of the reformulation. The sensory panel considered that NF and RF products had acceptable sensory characteristics.

A healthier oil combination and konjac gel as functional ingredients in low-fat pork liver pâté.

Healthier lipid pâtés were formulated by reducing the fat content and/or replacing the pork backfat by a healthier oil combination (olive, linseed and fish oils) and konjac gel (0-15%). The reformulation results were evaluated by composition (proximate analysis and fatty acid profile), technological properties (emulsion stability, colour, and texture), microbiological and sensory parameters of the pâtés. Pâtés with partial or total replacement of pork backfat had lower levels of saturated fatty acids (SFA) (27.4% and 21.3%) and monounsaturated fatty acids (MUFA) (49.8% and 42.5%), and higher levels of polyunsaturated fatty acids (PUFA) (22.4% and 35.6%) compared with control pâtés (32.2%, 58.2% and 9.04% respectively). The n-6/n-3 PUFA ratio was decreased from 6.78 (in control pâtés) to 0.79 and 0.48 when partial and total pork backfat respectively was replaced by a healthier oil combination. Although emulsion stability was affected by the formulation, in general all pâtés had good fat and water binding properties. The fat reduction produced a softer and more spreadable pâté, although no effect on penetration parameters was observed after by pork fat replacement by a healthier oil combination. The addition of 15% of konjac gel produced stiffer structures (as compared with 0 and 7%) which are very close to those of the control samples. No microbiological limitations were produced by the reformulation process, obtaining pâtés with acceptable sensory characteristics, similar to the control sample.

Doppler echocardiography in dilated and restrictive cardiomyopathies.

Dilated cardiomyopathy is characterized by systolic dysfunction and cardiac enlargement of unknown origin. Various Doppler modalities are useful to detect and quantitate atrioventricular regurgitation, which is common and contributes to clinical symptoms. Pulsed Doppler assessment of mitral and tricuspid inflow velocities shows a spectrum of findings indicative of abnormal diastolic function and hemodynamic status. When mitral regurgitation is more than moderate and heart failure is severe, the ratio between early inflow E wave to atrial inflow A wave peak velocities is increased. Mitral deceleration time may be short. When mitral regurgitation is trivial and left atrial pressure is not increased, abnormal relaxation may be detected as a low E:A ratio. Mitral deceleration time and isovolumic relaxation time are prolonged. In restrictive cardiomyopathy, there is an abrupt limitation in early ventricular filling due to abnormal compliance of endocardial or endomyocardial origin. Mitral and tricuspid inflow velocities show normal to increased early peak velocity, rapid deceleration time, low peak atrial velocity, and an increased E:A ratio. Differentiation between restriction and constriction might be possible by the demonstration in pericardial constriction of inspiratory decreases in mitral early inflow peak velocities and in prolongation of isovolumic relaxation time, with reciprocal changes on tricuspid inflow velocity profiles. In constriction, these respiratory variations are caused by the ventricular limitation to accommodate changes in venous return due to the pericardial shell. Doppler abnormalities and two-dimensional echocardiographic assessment of ventricular and atrial size and ejection fraction provide the practicing physician with valuable diagnostic information.

Death due to paroxysmal atrioventricular block during ambulatory electrocardiographic monitoring.

Witnessed sudden cardiac death due to paroxysmal atrioventricular (AV) block during ambulatory monitoring occurred in a 56-year-old female with primary conduction system disease. The control tracings showed right bundle branch block. Holter recordings obtained during the fatal event revealed paroxysmal complete AV block followed by ventricular asystole of approximately 13 seconds which, in turn, preceded the emergence of a slow idioventricular rhythm. The patient was definitely alive 5 minutes and 10 seconds following the onset of the AV block (since she activated the event marker in the recorder twice) and, possibly, 8 minutes later. Complete AV block persisted until the cessation of all cardiac activity, which took place 47 minutes following the occurrence of AV block. It is very likely that this patient could have been resuscitated in a city having a rapidly responding rescue squad.

Management of tachyarrhythmias with dual-chamber pacemakers.

Multiprogrammable dual-demand AV sequential (DVI, MN) pacemakers were implanted in twenty-three patients (in one of them a DVI, MN unit was used as a VVI, MN with the aid of an atrial plug) with supraventricular tachycardias after electrophysiological studies revealed a great variety of AV reentry circuits. The latter included tachycardias involving accessory pathways of the Kent type, manifest or concealed Wolff-Parkinson-White syndromes, nodo-ventricular (Mahaim) tracts, "enhanced" AV node (or extra AV nodal) pathways and dual AV pathways. In addition, multiprogrammable "non-committed" AV sequential (DVI, MN and DDD, M) pacemakers were permanently implanted to treat different forms of ventricular tachyarrhythmias that included: torsade de pointes in the Romano-Ward syndrome and Chagas' cardiomyopathy, ventricular tachycardia which is bradycardia-dependent (in Chagas' cardiomyopathy) and reciprocal beats induced by, and producing severe hemodynamic derangements in a patient with a conventional VVI unit. With small-size multiprogrammable units, arrhythmias may be treated by changing parameters non-invasively. By temporary inhibition, one may analyze the underlying rhythm and pacemaker dependency. In patients without chronic atrial flutter/fibrillation who require pacing and possibly tachyarrhythmia control, our experience with multiprogrammable "non-committed" AV sequential pacing has been very satisfactory. The evolution toward newer pacing modes which provide atrial sensing and tracking (DDD), and thus preserve AV synchrony over a wider range of atrial rates, may contribute even further to successful patient management. This may be applicable to pediatric patients as well.