CTC
Piracicaba, Brazil
CTC
Piracicaba, Brazil

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Elizaquivel P.,University of Valencia | Gabaldon J.A.,CTC | Aznar R.,University of Valencia | Aznar R.,CSIC - Institute of Agricultural Chemistry and Food Technology
Food Control | Year: 2011

Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. are foodborne pathogens frequently associated with foods such as poultry, ready-to-eat products, fruits and vegetables. PCR-based procedures are rapid, sensitive and accurate; in particular, real-time PCR (qPCR), which besides being an automated high-throughput technique, allows quantification of foodborne pathogens. In the present work, qPCR-based methods were applied for the quantitative detection of E. coli O157:H7, Salmonella spp. and L. monocytogenes in a total of 306 non-spiked food samples in a study carried out in two laboratories simultaneously. qPCR allowed the detection of the three pathogens in around 20% of the analyzed samples for each pathogen. Quantification results revealed the presence of the three pathogens mostly at levels between 102 and 104 cells/g. Besides quantification, the qPCR results (presence/absence) were compared with those of the standard mini-VIDAS system. In order to determine which were the "true" positive samples, conventional PCR was carried out after the corresponding enrichment for each pathogen. These results were considered as the gold standard for further analysis. The statistical analysis of global data recording the presence of E. coli O157:H7 and L. monocytogenes, together with data previously obtained for Salmonella spp., revealed that qPCR outperformed the mini-VIDAS procedures, in terms of both time and accuracy. Thus, these results proved qPCR to be useful as a rapid diagnostic test for the direct detection of pathogens in food, without the need for enrichment steps. © 2010 Elsevier Ltd.


PubMed | St Stephens Hospital and CTC
Type: Review | Journal: Annals of cardiac anaesthesia | Year: 2017

Cardiac practice involves the application of a range of pharmacological therapies. An anesthesiologist needs to keep pace with the rampant drug developments in the field of cardiovascular medicine for appropriate management in both perioperative and intensive care set-up, to strengthen his/her role as a perioperative physician in practice. The article reviews the changing trends and the future perspectives in major classes of cardiovascular medicine.


Benkahla J.,CTC | Baranger T.N.,INSA Lyon | Issartel J.,CTC
Experimental Mechanics | Year: 2012

In this paper, we deal with the mechanical behaviour of elastomeric sole shoes subjected to bending. First, a methodology for material parameter identification is described for a visco-hyperelastic constitutive law with discontinuous damage, modelling the Mullins effect. This constitutive law was implemented in the finite element software CODE-ASTER (Abbas and Baranger 2010). Then, numerical results of the bending behaviour of a simple geometric shoe sole model are compared to experimental measurements obtained with a stereoscopic vision system. Finally, an industrial application of dynamic bending sole shoe is presented and experimental results and simulated load history are compared. © 2012 Society for Experimental Mechanics.


Malik V.,CTC | Subramaniam A.,CTC | Kapoor P.M.,CTC
Annals of Cardiac Anaesthesia | Year: 2016

Newer noninvasive parameters are being used for perioperative detection of myocardial ischaemia. TDI and global strain rate are some of these parameters. TDI signal is a modification of the routine Doppler flow signal. It is obtained by using thresholding and filtering algorithms that reject echoes originating from the blood pool (by-passing the high pass filter). Set-Up of the machine by activating the TDI function allows decreasing the system gain using a low pass filter and eliminates the signal produced by blood flow. Doppler shift obtained from myocardial tissue motion are of higher amplitudes (reflectivity 40 dB higher) and move about 10 times slower than blood (velocity range: 0.06 to 0.24 m/s). Speckle tracking echocardiography (tissue tracking, 2D strain) utilizes routine gray-scale 2D echo images to calculate myocardial strain. Interactions of ultrasound with myocardium result in reflection and scattering. These interactions generate a finely gray-shaded, speckled pattern (acoustic marker). This speckled pattern is unique for each myocardial region and relatively stable throughout the cardiac cycle. Spatial and temporal image processing of acoustic speckles in both 2D and 3D allows for the calculation of myocardial velocity, strain, and Strain rate. © 2016 Annals of Cardiac Anaesthesia.


Lappa M.,CTC
International Journal for Multiscale Computational Engineering | Year: 2011

The relevance of self-organization, pattern formation, nonlinear phenomena, and nonequilibrium behavior in a wide range of problems related to macromolecular crystal engineering calls for a concerted approach using the tools of statistical physics, thermodynamics, fluid dynamics, nonlinear dynamics, mathematical modeling, and numerical simulation in synergy with experimentally oriented work. The reason behind such a need is that in many instances of relevance in this field one witnesses an interplay between molecular and macroscopic-level entities and processes. Along these lines, two models are defined here and discussed in detail, one dealing with issues of complex behavior at the microscopic level and the other referring to the strong nonlinear nature of macroscopic evolution. Such models share a common fundamental feature, a group of equations strictly related from a mathematical point of view to the kinetic conditions used to model mass transfer at the crystal surface. Model diversification then occurs on the basis of the desired scale length; i.e., according to the level of detail required by the analysis (local or global). If the local evolution of the crystal surface is the subject of the investigation (distribution of the local growth rate along the crystal face, shape instabilities, onset of surface depressions due to diffusive and/or convective effects, etc.; i.e., all those factors dealing with the local history of the shape) the model is conceived to provide microscopic and morphological details. For this specific case a kinetic-coefficient-based moving boundary numerical (computational fluid dynamics) strategy is carefully developed on the basis of the volume-of-fluid methods (also known as the volume tracking methods) and level-set techniques, which have become popular in the last years as numerical techniques capable of modeling complex multiphase problems as well as for their capability to undertake a fixed-grid solution without resorting to mathematical manipulations and transformations. On the contrary, if the size of the crystals is negligible with respect to the size of the reactor (i.e., if they are small and undergo only small dimensional changes with respect to the overall dimensions of the cell containing the feeding solution), the shape of the crystals is ignored and the proposed approach relies directly on an algebraic formulation of the nucleation events and on the application of an integral form of the mass balance kinetics for each protein crystal. The applicability and the suitability of the different submodels are discussed according to some worked examples of practical interest. Pattern formation in these processes is described here with respect to crystal shapes, nuclei spatial discrete arrangements, and the convective multicellular structures arising as a consequence of buoyancy forces, thus enriching the discussions with some interdisciplinary flavor. © 2011 by Begell House, Inc.


Kapoor P.,CTC | Irpachi K.,CTC
Annals of Cardiac Anaesthesia | Year: 2016

Simulation-based learning is a journey into the unchartered depths of three-dimensional reality of a topic, within one's own mind and soul. It brings forth a spiritual ecstasy. © 2016 Annals of Cardiac Anaesthesia | Published by Wolters Kluwer - Medknow.


Rayleigh-Bénard convection in finite-size enclosures exhibits really intricate features when turbulent states are reached and thermal plumes play a crucial role in a number of them. This complex mechanism may be regarded as a " machine" containing many different working parts: boundary layers, mixing zones, jets, and a relatively free and isothermal central region. These parts are generally regarded as the constitutive " ingredients" whose interplay leads to the emergence of a macroscopic pattern with well-defined properties. Like the Lorenz model (but with the due differences) such a complex structure has a prevailing two-dimensional nature and can be oriented clockwise or anticlockwise (both configurations are equally likely to occur and the flow can exhibit occasional and irregular " reversals" from one to the other without a change in magnitude). It is usually referred to in the literature as " wind of turbulence" or " flywheel" The present article provides insights into the possible origin of such dynamics and related patterning behavior (supported by " ad hoc" novel numerical simulations carried out for Pr=15 and O(103)≤Ra" O(1010)) together with a short exposition of existing theories, also illustrating open points and future directions of research. © 2011 Académie des sciences.


PubMed | CTC
Type: Journal Article | Journal: Annals of cardiac anaesthesia | Year: 2017

Serum lactate and base deficit have been shown to be a predictor of morbidity and mortality in critically ill patients. Poor preoperative oxygenation appears to be one of the significant factors that affects early mortality in tetralogy of Fallot (TOF). There is little published literature evaluating the utility of serum lactate, base excess (BE), and oxygen partial pressure (PO 2 ) as simple, widely available, prognostic markers in patients undergoing surgical repair of TOF.This prospective, observational study was conducted in 150 TOF patients, undergoing elective intracardiac repair. PO 2 , BE, and lactate levels at three different time intervals were recorded. Arterial blood samples were collected after induction (T1), after cardiopulmonary bypass (T2), and 48 h (T3) after surgery in the Intensive Care Unit (ICU). To observe the changes in PO 2 , BE, and lactate levels over a period of time, repeated measures analysis was performed with Bonferroni method. The receiver operating characteristics (ROC) analysis was used to find area under curve (AUC) and cutoff values of various biomarkers for predicting mortality in ICU.The patients who could not survive showed significant elevated lactate levels at baseline (T1) and postoperatively (T2) as compared to patients who survived after surgery (P < 0.001). However, in nonsurvivors, the BE value decreased significantly in the postoperative period in comparison to survivors (-2.8 4.27 vs. 5.04 2.06) (P < 0.001). In nonsurvivors, there was a significant fall of PO 2 to a mean value of 59.86 15.09 in ICU (T3), whereas those who survived had a PO 2 of 125.86 95.09 (P < 0.001). The ROC curve analysis showed that lactate levels (T3) have highest mortality predictive value (AUC: 96.9%) as compared to BE (AUC: 94.5%) and PO 2 (AUC: 81.1%).Serum lactate and BE may be used as prognostic markers to predict mortality in patients undergoing TOF repair. The routine analysis of these simple, fast, widely available, and cost-effective biomarkers should be encouraged to predict prognosis of TOF patients.


PubMed | BRAIRCH and CTC
Type: Review | Journal: Annals of cardiac anaesthesia | Year: 2017

The difficult airway (DA) is a common problem encountered in patients undergoing cardiac surgery. However, the challenge is not only just establishment of airway but also maintaining a definitive airway for the safe conduct of cardiopulmonary bypass from initiation to weaning after surgical correction or palliation, de-airing of cardiac chambers. This review describes the management of the DA in a cardiac theater environment. The primary aims are recognition of DA both anatomical and physiological, necessary preparations for (and management of) difficult intubation and extubation. All patients undergoing cardiac surgery should initially be considered as having potentially DA as many of them have poor physiologic reserve. Making the cardiac surgical theater environment conducive to DA management is as essential as it is to deal with low cardiac output syndrome or acute heart failure. Tube obstruction and/or displacement should be suspected in case of a new onset ventilation problem, especially in the recovery unit. Cardiac anesthesiologists are often challenged with DA while inducing general endotracheal anesthesia. They ought to be familiar with the DA algorithms and possess skill for using the latest airway adjuncts.


PubMed | CTC
Type: Review | Journal: Annals of cardiac anaesthesia | Year: 2017

Diastolic dysfunction is common in cardiac disease and an important finding independent of systolic function as it contributes to the signs and symptoms of heart failure. Tissue Doppler mitral early diastolic velocity (Ea) combined with peak transmitral early diastolic velocity (E) to obtain E/Ea ratio provides an estimate of the left ventricular (LV) filling pressure. However, E/Ea has a significant gray zone and less reliable in patients with preserved ejection fraction (>50%). Two-dimensional echocardiographic speckle tracking measure myocardial strain and strain rate (Sr) avoiding the Doppler-associated angulation errors and tethering artifacts. Global myocardial peak diastolic strain (Ds) and diastolic Sr (DSr) at the time of E and isovolumic relaxation combined with E (E/Ds and E/10 DSr) have been recently proposed as novel indices to determine LV filling pressure. The present article elucidates the methodology of studying diastology with strain echocardiography along with the advantages and limitations of the novel technique in light of the available literature.

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