Alejandro Mazzadi - Academia.edu (original) (raw)
Papers by Alejandro Mazzadi
![Research paper thumbnail of Cardiac retention of [<sup>11</sup>C]HED in genotyped long QT patients: a potential amplifier role for severity of the disease](https://attachments.academia-assets.com/112591032/thumbnails/1.jpg)
](American Journal of Physiology-heart and Circulatory Physiology, Sep 1, 2003
Clinical and Experimental Hypertension, 1998
Previous experiments showed that enalapril (EN) treatment as well as enalaprilic acid, when added... more Previous experiments showed that enalapril (EN) treatment as well as enalaprilic acid, when added to the perfusion bath, diminish the inotropic response of the papillary muscles to isoproterenol (ISO). The main objective of this study was to evaluate, in normal rats, the effect of EN on basal contractility and inotropic response to ISO on the whole perfused ventricles (Langendorff preparation). Blood pressure (BP), increase in body weight (IBW), ventricular weight/body weight ratio (R) and concentration of ventricular proteins and DNA were also analyzed. Five groups were studied: EN10: 5 mg/kg/day, 10 days; EN21(L): 5mg/kg/day, 21 days; EN21(H): 15 mg/kg/day, 21 days. C10 and C21 were untreated controls. Cardiac contractility was evaluated by the maximal developed pressure, maximal rate of rise of pressure and maximal velocity of relaxation; no changes were found due to EN treatments either on basal conditions or on ISO stimulation. Significant differences (p&amp;lt;0.05 vs C21) were: lower BP and R in EN21(L) and EN21(H), slower IBW in EN21(H), decreased ventricular DNA in EN21(H). In conclusion, daily treatment for ten or twenty one days with enalapril does not change either basal cardiac contractile performance or inotropic response to ISO in the Langendorff preparation. Longterm treatment with EN seems to modify nuclear processes involved in cardiomyocite DNA content.
Archives of Cardiovascular Diseases Supplements, 2011
Methods: Polymorphisms of the AGT, ACE (I/D) and AGTR1 (A1166C) genes in patients and controls we... more Methods: Polymorphisms of the AGT, ACE (I/D) and AGTR1 (A1166C) genes in patients and controls were analyzed using allele-specific PCR, and PCR-rflp. Results: A total of 140 healthy subjects and 119 individuals with MI were divided into two groups < 65 and > 65 years old. The evolution with age showed that the AGT M allele (P < 0.001) and the ACE I allele (P < 0.05) frequency decreased with age. The TT genotype frequency increased in patients with MI > 65 years (OR =3.52; 95% CI; 3.12-5.54). The AA genotype showed a similar behaviour (OR = 2.9; 95% CI; 1.11-5.6). The DD genotype increased in the MI > 65 group (OR = 6.66; 95% CI; 2.02-21.9). Serum ACE activity was positively associated to age (r=0.38, p=0.000). Patients with DD genotype > 65 years was significantly higher (119.
12th International Symposium on Medical Information Processing and Analysis, 2017
In geometric control model based methods, it is well known that if a nonlinear system has its rel... more In geometric control model based methods, it is well known that if a nonlinear system has its relative degree equal to the number of states in the neighborhood of a point of equilibrium, thus it is possible to perform a coordinate transformation and a state feedback that transforms the nonlinear system into a linear and controllable one. Stabilization of this system is possible by a simple linear control technique. This method is based on the exact cancellation of nonlinear terms. If the parameters are either time-varying or there is uncertainty in the nonlinear terms of the model, then cancellation would not be longer accurate. The modification of the control method with adaptive parameters, makes asymptotically exact the cancellation of the nonlinear terms and maintains the efficiency of the transformation. This paper presents a nonlinear adaptive control method based on exact linearization techniques applied to the automation of blood glucose regulation in Type-1 diabetes. Using continuous blood glucose monitoring as the input, the method provides the insulin infusion function as the output. Since the insulin infusion calculated drives blood glucose to normal levels, the method mimics the healthy pancreas function and it could be applied in artificial pancreas to control blood glucose in type 1 diabetic patients.
Buenos Aires. AR; Instituto de Investigaciones Gino Germani, UBA, 2011
La vacuna contra el HPV está disponible en Argentina desde el año 2008 y recientemente el Ministe... more La vacuna contra el HPV está disponible en Argentina desde el año 2008 y recientemente el Ministerio de Salud de la Nación ha anunciado su incorporación en el calendario oficial de vacunación. Diversos estudios han mostrado que la recomendación del médico en relación a la vacunación es un factor determinante en la aceptabilidad de la vacuna contra el HPV de la población. Es necesario entonces producir evidencia sobre los conocimientos y aceptabilidad de la vacuna contra el HPV entre los profesionales médicos. Dicha evidencia será utilizada en la elaboración de estrategias de capacitación y difusión específicas que aseguren una alta cobertura de vacunaciónÁrea de Salud, Economía y Socieda
Japan Marketing Journal, 2021
Coronavirus disease (COVID) related confusion has transformed people's behavior. At the same time... more Coronavirus disease (COVID) related confusion has transformed people's behavior. At the same time, value creation in the customer's lifeword has become more diverse, complex, and sophisticated. As a result, for firms engaged in value co-creation with customers, the knowledge and skills demanded by customers are now beyond the scope of individual firms. Based on this perspective, value co-creation marketing needs to respond in new ways to fulfill these demands. Under such circumstances, firms that offer a large variety of knowledge and skills required by customers have emerged through a new form of corporate system, which is called a local platform. Therefore, in this study, we discussed a further reach point of value co-creation marketing research, clarified the theoretical and practical issues in today's coronavirus disaster, and demonstrated the characteristics of the new corporate system through a case study dealing with concern of a local platform. Based on these discussions, we looked forward to new directions for marketing research in the future.
Academic Radiology, 2002
Factor analysis of medical image sequences (FAMIS) applied to gadolinium chelate-enhanced subseco... more Factor analysis of medical image sequences (FAMIS) applied to gadolinium chelate-enhanced subsecond magnetic resonance (MR) imaging was evaluated as a postprocessing method for assessing myocardial perfusion in coronary artery disease (CAD). To assess the accuracy of motion correction, five normal volunteers underwent MR imaging at rest. Thirteen patients with well-documented CAD and no myocardial infarction underwent MR imaging at rest and after dipyridamole administration. After motion correction, a single myocardial tissue factor (FAMISt) image was obtained with FAMIS for each raw MR imaging series acquisition. To evaluate how FAMIS could improve the analysis of these acquisitions, five readers visually assessed myocardial perfusion with FAMISt and raw MR images, and a multicase, multireader receiver operating characteristic analysis was performed. FAMISt images significantly improved detection of the perfusion defects when compared with raw MR images (P = .002). Areas under the receiver operating characteristic curves ranged from 0.84 to 0.93 with FAMISt images and from 0.48 to 0.85 with raw MR images. FAMIS applied to first-pass MR imaging series provided myocardial perfusion images that improve the objective assessment of myocardial perfusion in patients with CAD.
AJP: Heart and Circulatory Physiology, 2004
In severe coronary artery disease (CAD), it has been shown that intramyocardial inotropic reserve... more In severe coronary artery disease (CAD), it has been shown that intramyocardial inotropic reserve as assessed with tagged magnetic resonance imaging (MRI) is uniformly distributed among positron emission tomography (PET) patterns reflecting normal or concomitant reductions in perfusion and glucose metabolism. This preliminary study aimed to delineate the relationship between preoperative values of intramyocardial inotropic reserve (in different PET patterns of perfusion and glucose uptake) and intramyocardial functional outcome after surgical revascularization in severe CAD. Twelve patients underwent preoperative tagged MRI (baseline, 10 μg·kg−1·min−1 of dobutamine), H215O/[18F]fluorodeoxyglucose PET imaging, and postoperative resting tagged MRI. Regional midmyocardial circumferential shortening ( Ecc, in %) and PET patterns (normal, match viable, mismatch viable, and infarcted) were assessed in three tagged MRI/PET short-axis slices. Ecc at baseline ranged from 12 ± 6 to 8 ± 5 and ...
AJP: Heart and Circulatory Physiology, 2004
The impact of blood flow reductions on the intramyocardial inotropic reserve has not yet been est... more The impact of blood flow reductions on the intramyocardial inotropic reserve has not yet been established in coronary artery disease (CAD). We therefore evaluated in severe CAD the relationship between positron emission tomography (PET) patterns of perfusion and glucose uptake and the corresponding tagged magnetic resonance imaging (tagged MRI) values of midmyocardial strains under low-dose dobutamine. Eighteen patients underwent tagged MRI (at rest, with dobutamine) and H 152O/18Ffluorodeoxyglucose PET. Regional midmyocardial circumferential shortening ( Ecc) and PET patterns (normal, match viable, mismatch viable, and infarcted) were assessed in three tagged MRI/PET short-axis slices. Regional Ecc at rest correlated with both perfusion ( r = 0.49) and glucose uptake ( r = 0.58). The presence of the inotropic reserve was similar in normal, match viable, and infarcted (∼40% of regions vs. 52% in mismatch viable, P…
AJP: Heart and Circulatory Physiology, 2006
Patients with severe chronic coronary artery disease (CAD) exhibit a highly altered myocardial pa... more Patients with severe chronic coronary artery disease (CAD) exhibit a highly altered myocardial pattern of perfusion, metabolism, and mechanical performance. In this context, the diagnosis of stunning remains elusive not only because of methodological and logistic considerations, but also because of the pathophysiological characteristics of the myocardium of these patients. In addition, a number of alternative pathophysiological mechanisms may act by mimicking the functional manifestations usually attributed to stunning. The present review describes three mechanisms that could theoretically lead to reversible mechanical dysfunction in these patients: myocardial wall stress, the tethering effect, and myocardial expression and release of auto- and paracrine agents. Attention is focused on the role of these mechanisms in scintigraphically “normal” regions (i.e., regions usually showing normal perfusion, glucose metabolism, and cellular integrity as assessed by nuclear imaging techniques...
Journal of Cardiovascular Pharmacology, 1991
![Research paper thumbnail of Cardiac retention of [11C]HED in genotyped long QT patients: a potential amplifier role for severity of the disease](https://attachments.academia-assets.com/88380865/thumbnails/1.jpg)
](American journal of physiology. Heart and circulatory physiology, 2003
Although mutations in cardiac sodium and potassium channel genes are associated with congenital l... more Although mutations in cardiac sodium and potassium channel genes are associated with congenital long QT syndrome (LQTS), a "modifier" role of the sympathetic nervous system was proposed to explain the distinct severity of the disease. We evaluated cardiac sympathetic innervation using [11C]hydroxyephedrine ([11C]HED) and positron emission tomography (PET) in genotyped LQTS patients. H215O and [11C]HED PET studies were performed in 11 patients (5 symptomatic) and 8 controls. Perfusion and [11C]HED images were depicted as 36-sector polar maps. Sectorial values of perfusion (H2O%), absolute (HEDRet) and relative retention (HED%Ret) of [11C]HED, and the ratio of HED%Ret to H2O% (HED%Ret/H2O%) were calculated. Normal databases were obtained from controls. Sectorial values below 2SD database values were defined as "outside sectors." Controls and patients showed similar sectorial perfusion. Sectorial HEDRet did not differ between groups, but means of HED%Ret were lower ...
International Journal of Embedded Systems, 2021
ad-teaching.informatik.uni-freiburg. …
Methods Experiments were performed in male Wistar rats (n= 25) weighing 330 g. All the rats had a... more Methods Experiments were performed in male Wistar rats (n= 25) weighing 330 g. All the rats had access to a standard dry meal and water ad libitum. The rats were anesthetized with sodium pentobarbital (40 mg/kg ip), and the heart was rapidly removed and placed in an ...
Medical Engineering & Physics
Circulation, Oct 28, 2008
Salud Publica De Mexico, 2012
Aceptabilidad y conocimientos sobre la vacunación contra el virus del papiloma humano (VPH) en mé... more Aceptabilidad y conocimientos sobre la vacunación contra el virus del papiloma humano (VPH) en médicos ginecólogos de la Argentina.
Http Digital Bl Fcen Uba Ar, 1997
Total heat production and mechanical evolution were studied in electrically stimulated (1.5 Hz) r... more Total heat production and mechanical evolution were studied in electrically stimulated (1.5 Hz) rat's ventricles perfused by Langendorff technique and subjected to ischemia (Isch)and reperfusion(Rep) (45 min both). Temperature ffect was evaluated at 25, 30 and 35°C. Four identified active heat components from a single contraction (H1 to H4)(Ponce-Hornoset al, Pflugers Arch-Eur J Physiol 429;1995)) were analyzed during the first 10 min of ischemia. Resting (RP) and developed pressure(P) and total heat production (Et) were simultaneously measured on isovolumetric hearts placed in a calorimeter (Ponce-Hornos et al, Am J of Physiol 243;l982). From these results a fall in pH, as well as changes in ATP free energy, were discarded
Journal of Physics: Conference Series, 2016
Flat systems are a generalization of linear systems, but the techniques used for controlling flat... more Flat systems are a generalization of linear systems, but the techniques used for controlling flat systems are much different than many of the existing techniques for linear systems. In this paper we present the flatness-based control of blood glucose regulation in human system. A non-near model, he Bergman Minimal Model, is used o represent he dynamics of blood regulation in humans and because of the flatness property, he system variables can be expressed as functions of he at output and heir time derivatives and a control aw developed.
American Journal of Physiology-heart and Circulatory Physiology, Sep 1, 2003
Clinical and Experimental Hypertension, 1998
Previous experiments showed that enalapril (EN) treatment as well as enalaprilic acid, when added... more Previous experiments showed that enalapril (EN) treatment as well as enalaprilic acid, when added to the perfusion bath, diminish the inotropic response of the papillary muscles to isoproterenol (ISO). The main objective of this study was to evaluate, in normal rats, the effect of EN on basal contractility and inotropic response to ISO on the whole perfused ventricles (Langendorff preparation). Blood pressure (BP), increase in body weight (IBW), ventricular weight/body weight ratio (R) and concentration of ventricular proteins and DNA were also analyzed. Five groups were studied: EN10: 5 mg/kg/day, 10 days; EN21(L): 5mg/kg/day, 21 days; EN21(H): 15 mg/kg/day, 21 days. C10 and C21 were untreated controls. Cardiac contractility was evaluated by the maximal developed pressure, maximal rate of rise of pressure and maximal velocity of relaxation; no changes were found due to EN treatments either on basal conditions or on ISO stimulation. Significant differences (p&amp;lt;0.05 vs C21) were: lower BP and R in EN21(L) and EN21(H), slower IBW in EN21(H), decreased ventricular DNA in EN21(H). In conclusion, daily treatment for ten or twenty one days with enalapril does not change either basal cardiac contractile performance or inotropic response to ISO in the Langendorff preparation. Longterm treatment with EN seems to modify nuclear processes involved in cardiomyocite DNA content.
Archives of Cardiovascular Diseases Supplements, 2011
Methods: Polymorphisms of the AGT, ACE (I/D) and AGTR1 (A1166C) genes in patients and controls we... more Methods: Polymorphisms of the AGT, ACE (I/D) and AGTR1 (A1166C) genes in patients and controls were analyzed using allele-specific PCR, and PCR-rflp. Results: A total of 140 healthy subjects and 119 individuals with MI were divided into two groups < 65 and > 65 years old. The evolution with age showed that the AGT M allele (P < 0.001) and the ACE I allele (P < 0.05) frequency decreased with age. The TT genotype frequency increased in patients with MI > 65 years (OR =3.52; 95% CI; 3.12-5.54). The AA genotype showed a similar behaviour (OR = 2.9; 95% CI; 1.11-5.6). The DD genotype increased in the MI > 65 group (OR = 6.66; 95% CI; 2.02-21.9). Serum ACE activity was positively associated to age (r=0.38, p=0.000). Patients with DD genotype > 65 years was significantly higher (119.
12th International Symposium on Medical Information Processing and Analysis, 2017
In geometric control model based methods, it is well known that if a nonlinear system has its rel... more In geometric control model based methods, it is well known that if a nonlinear system has its relative degree equal to the number of states in the neighborhood of a point of equilibrium, thus it is possible to perform a coordinate transformation and a state feedback that transforms the nonlinear system into a linear and controllable one. Stabilization of this system is possible by a simple linear control technique. This method is based on the exact cancellation of nonlinear terms. If the parameters are either time-varying or there is uncertainty in the nonlinear terms of the model, then cancellation would not be longer accurate. The modification of the control method with adaptive parameters, makes asymptotically exact the cancellation of the nonlinear terms and maintains the efficiency of the transformation. This paper presents a nonlinear adaptive control method based on exact linearization techniques applied to the automation of blood glucose regulation in Type-1 diabetes. Using continuous blood glucose monitoring as the input, the method provides the insulin infusion function as the output. Since the insulin infusion calculated drives blood glucose to normal levels, the method mimics the healthy pancreas function and it could be applied in artificial pancreas to control blood glucose in type 1 diabetic patients.
Buenos Aires. AR; Instituto de Investigaciones Gino Germani, UBA, 2011
La vacuna contra el HPV está disponible en Argentina desde el año 2008 y recientemente el Ministe... more La vacuna contra el HPV está disponible en Argentina desde el año 2008 y recientemente el Ministerio de Salud de la Nación ha anunciado su incorporación en el calendario oficial de vacunación. Diversos estudios han mostrado que la recomendación del médico en relación a la vacunación es un factor determinante en la aceptabilidad de la vacuna contra el HPV de la población. Es necesario entonces producir evidencia sobre los conocimientos y aceptabilidad de la vacuna contra el HPV entre los profesionales médicos. Dicha evidencia será utilizada en la elaboración de estrategias de capacitación y difusión específicas que aseguren una alta cobertura de vacunaciónÁrea de Salud, Economía y Socieda
Japan Marketing Journal, 2021
Coronavirus disease (COVID) related confusion has transformed people's behavior. At the same time... more Coronavirus disease (COVID) related confusion has transformed people's behavior. At the same time, value creation in the customer's lifeword has become more diverse, complex, and sophisticated. As a result, for firms engaged in value co-creation with customers, the knowledge and skills demanded by customers are now beyond the scope of individual firms. Based on this perspective, value co-creation marketing needs to respond in new ways to fulfill these demands. Under such circumstances, firms that offer a large variety of knowledge and skills required by customers have emerged through a new form of corporate system, which is called a local platform. Therefore, in this study, we discussed a further reach point of value co-creation marketing research, clarified the theoretical and practical issues in today's coronavirus disaster, and demonstrated the characteristics of the new corporate system through a case study dealing with concern of a local platform. Based on these discussions, we looked forward to new directions for marketing research in the future.
Academic Radiology, 2002
Factor analysis of medical image sequences (FAMIS) applied to gadolinium chelate-enhanced subseco... more Factor analysis of medical image sequences (FAMIS) applied to gadolinium chelate-enhanced subsecond magnetic resonance (MR) imaging was evaluated as a postprocessing method for assessing myocardial perfusion in coronary artery disease (CAD). To assess the accuracy of motion correction, five normal volunteers underwent MR imaging at rest. Thirteen patients with well-documented CAD and no myocardial infarction underwent MR imaging at rest and after dipyridamole administration. After motion correction, a single myocardial tissue factor (FAMISt) image was obtained with FAMIS for each raw MR imaging series acquisition. To evaluate how FAMIS could improve the analysis of these acquisitions, five readers visually assessed myocardial perfusion with FAMISt and raw MR images, and a multicase, multireader receiver operating characteristic analysis was performed. FAMISt images significantly improved detection of the perfusion defects when compared with raw MR images (P = .002). Areas under the receiver operating characteristic curves ranged from 0.84 to 0.93 with FAMISt images and from 0.48 to 0.85 with raw MR images. FAMIS applied to first-pass MR imaging series provided myocardial perfusion images that improve the objective assessment of myocardial perfusion in patients with CAD.
AJP: Heart and Circulatory Physiology, 2004
In severe coronary artery disease (CAD), it has been shown that intramyocardial inotropic reserve... more In severe coronary artery disease (CAD), it has been shown that intramyocardial inotropic reserve as assessed with tagged magnetic resonance imaging (MRI) is uniformly distributed among positron emission tomography (PET) patterns reflecting normal or concomitant reductions in perfusion and glucose metabolism. This preliminary study aimed to delineate the relationship between preoperative values of intramyocardial inotropic reserve (in different PET patterns of perfusion and glucose uptake) and intramyocardial functional outcome after surgical revascularization in severe CAD. Twelve patients underwent preoperative tagged MRI (baseline, 10 μg·kg−1·min−1 of dobutamine), H215O/[18F]fluorodeoxyglucose PET imaging, and postoperative resting tagged MRI. Regional midmyocardial circumferential shortening ( Ecc, in %) and PET patterns (normal, match viable, mismatch viable, and infarcted) were assessed in three tagged MRI/PET short-axis slices. Ecc at baseline ranged from 12 ± 6 to 8 ± 5 and ...
AJP: Heart and Circulatory Physiology, 2004
The impact of blood flow reductions on the intramyocardial inotropic reserve has not yet been est... more The impact of blood flow reductions on the intramyocardial inotropic reserve has not yet been established in coronary artery disease (CAD). We therefore evaluated in severe CAD the relationship between positron emission tomography (PET) patterns of perfusion and glucose uptake and the corresponding tagged magnetic resonance imaging (tagged MRI) values of midmyocardial strains under low-dose dobutamine. Eighteen patients underwent tagged MRI (at rest, with dobutamine) and H 152O/18Ffluorodeoxyglucose PET. Regional midmyocardial circumferential shortening ( Ecc) and PET patterns (normal, match viable, mismatch viable, and infarcted) were assessed in three tagged MRI/PET short-axis slices. Regional Ecc at rest correlated with both perfusion ( r = 0.49) and glucose uptake ( r = 0.58). The presence of the inotropic reserve was similar in normal, match viable, and infarcted (∼40% of regions vs. 52% in mismatch viable, P…
AJP: Heart and Circulatory Physiology, 2006
Patients with severe chronic coronary artery disease (CAD) exhibit a highly altered myocardial pa... more Patients with severe chronic coronary artery disease (CAD) exhibit a highly altered myocardial pattern of perfusion, metabolism, and mechanical performance. In this context, the diagnosis of stunning remains elusive not only because of methodological and logistic considerations, but also because of the pathophysiological characteristics of the myocardium of these patients. In addition, a number of alternative pathophysiological mechanisms may act by mimicking the functional manifestations usually attributed to stunning. The present review describes three mechanisms that could theoretically lead to reversible mechanical dysfunction in these patients: myocardial wall stress, the tethering effect, and myocardial expression and release of auto- and paracrine agents. Attention is focused on the role of these mechanisms in scintigraphically “normal” regions (i.e., regions usually showing normal perfusion, glucose metabolism, and cellular integrity as assessed by nuclear imaging techniques...
Journal of Cardiovascular Pharmacology, 1991
American journal of physiology. Heart and circulatory physiology, 2003
Although mutations in cardiac sodium and potassium channel genes are associated with congenital l... more Although mutations in cardiac sodium and potassium channel genes are associated with congenital long QT syndrome (LQTS), a "modifier" role of the sympathetic nervous system was proposed to explain the distinct severity of the disease. We evaluated cardiac sympathetic innervation using [11C]hydroxyephedrine ([11C]HED) and positron emission tomography (PET) in genotyped LQTS patients. H215O and [11C]HED PET studies were performed in 11 patients (5 symptomatic) and 8 controls. Perfusion and [11C]HED images were depicted as 36-sector polar maps. Sectorial values of perfusion (H2O%), absolute (HEDRet) and relative retention (HED%Ret) of [11C]HED, and the ratio of HED%Ret to H2O% (HED%Ret/H2O%) were calculated. Normal databases were obtained from controls. Sectorial values below 2SD database values were defined as "outside sectors." Controls and patients showed similar sectorial perfusion. Sectorial HEDRet did not differ between groups, but means of HED%Ret were lower ...
International Journal of Embedded Systems, 2021
ad-teaching.informatik.uni-freiburg. …
Methods Experiments were performed in male Wistar rats (n= 25) weighing 330 g. All the rats had a... more Methods Experiments were performed in male Wistar rats (n= 25) weighing 330 g. All the rats had access to a standard dry meal and water ad libitum. The rats were anesthetized with sodium pentobarbital (40 mg/kg ip), and the heart was rapidly removed and placed in an ...
Medical Engineering & Physics
Circulation, Oct 28, 2008
Salud Publica De Mexico, 2012
Aceptabilidad y conocimientos sobre la vacunación contra el virus del papiloma humano (VPH) en mé... more Aceptabilidad y conocimientos sobre la vacunación contra el virus del papiloma humano (VPH) en médicos ginecólogos de la Argentina.
Http Digital Bl Fcen Uba Ar, 1997
Total heat production and mechanical evolution were studied in electrically stimulated (1.5 Hz) r... more Total heat production and mechanical evolution were studied in electrically stimulated (1.5 Hz) rat's ventricles perfused by Langendorff technique and subjected to ischemia (Isch)and reperfusion(Rep) (45 min both). Temperature ffect was evaluated at 25, 30 and 35°C. Four identified active heat components from a single contraction (H1 to H4)(Ponce-Hornoset al, Pflugers Arch-Eur J Physiol 429;1995)) were analyzed during the first 10 min of ischemia. Resting (RP) and developed pressure(P) and total heat production (Et) were simultaneously measured on isovolumetric hearts placed in a calorimeter (Ponce-Hornos et al, Am J of Physiol 243;l982). From these results a fall in pH, as well as changes in ATP free energy, were discarded
Journal of Physics: Conference Series, 2016
Flat systems are a generalization of linear systems, but the techniques used for controlling flat... more Flat systems are a generalization of linear systems, but the techniques used for controlling flat systems are much different than many of the existing techniques for linear systems. In this paper we present the flatness-based control of blood glucose regulation in human system. A non-near model, he Bergman Minimal Model, is used o represent he dynamics of blood regulation in humans and because of the flatness property, he system variables can be expressed as functions of he at output and heir time derivatives and a control aw developed.