Isabel María Irurzun - Academia.edu (original) (raw)

Papers by Isabel María Irurzun

Global Heart, 2016

Introduction: This is a new kind of trial combining TCM and Western medicine. Objectives: To inve... more Introduction: This is a new kind of trial combining TCM and Western medicine. Objectives: To investigate the treatment effect, advantages and safety of combining TCM of tianma-gouteng decoction and L-amlodipine besylate in patients with essential hypertension (EH). Methods: 150 patients with EH were randomly divided into two groups: control group (n¼75) were treated with L-amlodipine besylate 2.5mg qd; treatment group (n¼75) were treated with the same dose of L-amlodipine besylate and plused TCM 150ml tid. The data were assessed at baseline and after treatment for 4 weeks. Results: After treatment, the clinical symptoms of headache, dizziness, palpitation, insomnia etc. in the two groups were relieved and were earlier and more significant in treatment group (P<0.05). CBP levels were significantly reduced compared to baseline(all P<0.01) in two groups respectively, and the reduction amplitude was more significant in treatment group [(147.28AE13.15)/(90.36AE11.17) vs (138.33AE10.67)/(83.25AE9.32)mmHg,P<0.05]. The values of 24hSBP,24hDBP,dSBP,dDBP,nSBP,nSBP,dSBPL,dDBPL,nSBPL and nDBPL were declined obviously compared to baseline(all P<0.01) in every group. 24hSBP,dSBP,nSBP and dSBPL, nSBPL were declined significantly compared to those in treatment group than in control group after treatment[(137.09AE12.71) vs (131.28AE11.90),(139.07AE13.12) vs (132.35AE10.77,(131.50AE12.61) vs (122.93AE13.16) mmHg and (46.67AE32.18)% vs (29.47AE23.93)%,(62.21AE31.35)% vs (43.19AE32.11)%, all P<0.05]. However, 24hDBP,dDBP,nDBP and dDBPL, nDBPL were no significant difference between two groups after treatment[(83.26AE10.07) vs (82.91AE9.34,(85.50AE13.72) vs (84.68AE10.28) g,(79.61AE12.57) vs (78.13AE11.18) mmHg and (38.38AE30.67)% vs (37.70AE28.63)%,(46.80AE31.75)% vs (46.19AE30.35)%,all P>0.05)].The T/p ratio was no significant difference between two groups[(0.69AE0.11)/(0.68AE0.13) vs (0.70AE0.13)/ (0.68AE0.32),P>0.05].No serious side effects were observed in two groups. Conclusion: (1)The symptoms of EH can be relieved obviously by TCM or L-amlodipine besylate. (2) TCM can reduce 24hSBP,dSBP and nSBP and can not reduce 24hDBP,dDBP and nDBP. (3) There are mult-aspect advantages of symptomatic improvement,SBP dropping,lesser side effective that in the patients by the therapy of combining tianma gouteng decoction with lamlodipine besylate.This is a new way to treat hypertension by combination therapy.

Univ Kragujevac, Feb 1, 2014

In the present paper we exactly solve the distributed parameter stochastic model of the heterogen... more In the present paper we exactly solve the distributed parameter stochastic model of the heterogeneous catalytic reaction 2A + B 2 → 2AB and calculate the average number of reactive steps necessary to deactivate the lattice first,< t >. Results are compared with Monte Carlo simulations. < t > shows a nonmonotonic behavior with the sticking coefficient probability s and the desorption probability p d , reaching a maximum value that depends on s, p d and the lattice size N .

Physical Review E, 2021

In this work we study the fractal properties of diffusion-limited aggregation (DLA) clusters grow... more In this work we study the fractal properties of diffusion-limited aggregation (DLA) clusters grown on spherical surfaces. Diffusion-limited aggregation clusters, or DLA trees, are highly branched fractal clusters formed by the adhesion of particles. In two-dimensional media, DLA clusters have a fractal dimension D f = 1.70 in the continuous limit. In some physical systems, the existence of characteristic lengths leads us to model them as discrete systems. Such characteristic lengths may result also from limitations in measuring instruments, for example, the resolution of biomedical imaging systems. We simulate clusters for different particle sizes and examine the influence of discretization by exploring the systems in terms of the relationship between the particle size r and the radius of the sphere R. We also study the effect of stereographic projection on the fractal properties of DLA clusters. Both discretization and projection alter the fractal dimension of DLA clusters grown on curved surfaces and must be considered in the interpretation of photographic biomedical images.

Chemical Physics Letters, 2022

Heart rate variability (HRV) is mainly controlled by the autonomic nervous system (ANS) interacti... more Heart rate variability (HRV) is mainly controlled by the autonomic nervous system (ANS) interacting with receptors on the sinoatrial node (SAN). HRV is influenced by many several factors such as chemical, hormonal and neural modulations, circadian changes, exercise, emotions, posture, and preload. The heart rate adaptation to changing factors is carried out by the activity of a variety of regulatory subsystems and results in a complex linear and non- linear time behaviour, which changes with age, gender and pathological conditions. Many studies explore an age range of 1-99 years. This study focused on the development of a database of long-term time series of healthy volunteers aged between 1 month and 55 years.

In this work we present a study on the methane oxidation reaction on Cr2O3 in the presence of sul... more In this work we present a study on the methane oxidation reaction on Cr2O3 in the presence of sulfur dioxide using both infrared spectroscopy and simulations based on the density functional theory. The purpose of the work is to know the reasons why sulfur dioxide decreases the activation energy of the methane oxidation reaction. We found that sulfur dioxide promotes oxygen dissociation through the formation of sulfite species. Dissociated oxygen favors the dehydrogenation of methane, the formation of methoxy species, formaldehyde, dioxymethylene, and methanol.

En el presente trabajo se estudian las estructuras y geometrias moleculares del CH4 , SO2 y O2 ad... more En el presente trabajo se estudian las estructuras y geometrias moleculares del CH4 , SO2 y O2 adsorbidos sobre la superficie de Cr2O3 (0001). Mediante calculos computacionales basados en la Teoria Funcional de la Densidad (DFT) analizamos los sitios mas aptos para llevar a cabo la adsorcion de cada una de las moleculas mencionadas, asi como la influencia de de cada especie sobre la adsorcion y disociacion de las otras. Los resultados permiten comprender la activacion que produce la presencia de SO2 de la superficie de Cr2O3 (0001) para la oxidacion de CH4 , como fue verificado experimentalmente

espanolEn el presente trabajo se describen las caracteristicas fisicoquimicas de los compuestos F... more espanolEn el presente trabajo se describen las caracteristicas fisicoquimicas de los compuestos Flavonoides con mayor grado de estudio hasta la actualidad, y su aporte a la medicina tradicional y natural, junto con sus aplicaciones en el campo de la industria alimenticia. Los principales objetivos del mismo son, por un lado, proveer informacion fisicoquimica basica sobre las estructuras moleculares de los diferentes tipos con mayores aplicaciones industriales y medicinales hasta el presente, y por otro, relacionar las propiedades naturales de los alimentos que los contienen con los beneficios a la salud humana. EnglishIn this article, we describe the physicochemical characteristics of those flavonoid compounds which have been more deeply studied up to the present. We also analyze their contribution to traditional and natural medicine, together with their applications in food industry. The main objectives are, on the one hand, to provide basic physicochemical information about the mo...

Anales AFA, 2021

In this work we perform a theoretical study of dehydrogenation process of CH4 on O2– in both mole... more In this work we perform a theoretical study of dehydrogenation process of CH4 on O2– in both molecular and dissociative states - previously adsorbed on Cr2O3(0001). Calculations are based on Density Functional Theory (DFT). The results show the methanol formation form the adsorption of CH4 on O2 in dissociative state with a formationenergy5:14 eV. Also formaldehyde was formed by the reaction of CH2with molecular O2(Eads=6:09 eV) and dioxymethylene by the reaction of CH2with O2 previously adsorbed in dissociative state on Cr2O3(0001), withEads=8:17 eV. Finally, the vibrational modes found by DFT for each of the species were compared, which are in good agreement with those of reference bibliography. This allows us to support the values found both by technical calculations and by experimental methods.

MATCH Communications in Mathematical and in Computer Chemistry, 2021

In the present paper we extend the exact solution previously obtained for the heterogeneous catal... more In the present paper we extend the exact solution previously obtained for the heterogeneous catalytic reaction 2A + B2 → 2AB on small domains, to arbitrary lattice sizes () and calculate the average number of reactive steps necessary to poison the lattice first, . We determine as a function of through Monte Carlo simulations previously contrasted with the exact solution in lattices. We show that follows a power law with , without appreciable transient behaviors, and a scale factor () dependent on the two parameters of the model, the sticking coefficient probability and the desorption probability . The dependence of on both and is determined.

La emisión de dióxido de azufre por chimeneas industriales constituye una de las principales prob... more La emisión de dióxido de azufre por chimeneas industriales constituye una de las principales problemáticas ambientales, con las consecuencias ya conocidas de problemas para la salud de la población y con efectos nocivos como la lluvia ácida. En las chimeneas industriales, la reducción del SO2 ocurre por reacción con CH4, a la vez que este último es oxidado a CO2. La reacción completa ocurre en presencia del oxígeno atmosférico. Esta conversión es de gran importancia a nivel ambiental debido a que cada molécula de CH4 contamina como si se emitieran 21 moléculas de CO2 a la atmósfera (por lo tanto, al emitir CO2 en su lugar, se provoca un efecto contaminante 21 veces menor). El objetivo del presente trabajo de tesis doctoral fue el estudio del comportamiento de adsorción y reducción catalítica de SO2 sobre Cr2O3/Al2O3 en presencia de CH4 y O2 a altas temperaturas, a nivel experimental y teórico. Durante este trabajo, se variaron condiciones experimentales como las proporciones de los ...

IEEE Transactions on Dielectrics and Electrical Insulation, 2016

We report the results of electrical treeing tests carried out on a range of silicone dielectric g... more We report the results of electrical treeing tests carried out on a range of silicone dielectric gel samples made by varying the ratio of the same two components used for cross-linking a commercial silicone gel. These samples range from liquids to elastomers via two-phase gels. The extent of the curing is followed by means of FTIR spectroscopy and the samples are characterized through their dynamical mechanical properties. It is shown that the gel samples exhibit treeing behavior that includes features typical of both liquids and solids. A filamentary structure is produced that has permanence together with attached bubbles that self-heal locally during treeing, although differences in detail were found depending on the degree of curing. Removal of the treeing voltage allows a more substantial self-healing to occur. This behavior is discussed in terms of the two-phase liquid-solid nature of the silicone gels.

2015 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), 2015

Electrical treeing in silicone polymers has been investigated using a typical pin-plane geometry.... more Electrical treeing in silicone polymers has been investigated using a typical pin-plane geometry. The purpose of this work was to investigate the effect of ac field frequency upon the structure of treeing damage in a range of silicone dielectric materials. The liquid components were cured using different crosslinking ratios and hence both gels and elastomers were formed possessing a range of mechanical stiffness. These materials were characterized mechanically with an AR-G2 Rheometer. The results suggest that there is a clear dependence of the tree fractal dimension upon the applied ac voltage frequency and the sample's microstructure as characterized by oscillating rheometry.

Global Heart, 2016

Introduction: This is a new kind of trial combining TCM and Western medicine. Objectives: To inve... more Introduction: This is a new kind of trial combining TCM and Western medicine. Objectives: To investigate the treatment effect, advantages and safety of combining TCM of tianma-gouteng decoction and L-amlodipine besylate in patients with essential hypertension (EH). Methods: 150 patients with EH were randomly divided into two groups: control group (n¼75) were treated with L-amlodipine besylate 2.5mg qd; treatment group (n¼75) were treated with the same dose of L-amlodipine besylate and plused TCM 150ml tid. The data were assessed at baseline and after treatment for 4 weeks. Results: After treatment, the clinical symptoms of headache, dizziness, palpitation, insomnia etc. in the two groups were relieved and were earlier and more significant in treatment group (P<0.05). CBP levels were significantly reduced compared to baseline(all P<0.01) in two groups respectively, and the reduction amplitude was more significant in treatment group [(147.28AE13.15)/(90.36AE11.17) vs (138.33AE10.67)/(83.25AE9.32)mmHg,P<0.05]. The values of 24hSBP,24hDBP,dSBP,dDBP,nSBP,nSBP,dSBPL,dDBPL,nSBPL and nDBPL were declined obviously compared to baseline(all P<0.01) in every group. 24hSBP,dSBP,nSBP and dSBPL, nSBPL were declined significantly compared to those in treatment group than in control group after treatment[(137.09AE12.71) vs (131.28AE11.90),(139.07AE13.12) vs (132.35AE10.77,(131.50AE12.61) vs (122.93AE13.16) mmHg and (46.67AE32.18)% vs (29.47AE23.93)%,(62.21AE31.35)% vs (43.19AE32.11)%, all P<0.05]. However, 24hDBP,dDBP,nDBP and dDBPL, nDBPL were no significant difference between two groups after treatment[(83.26AE10.07) vs (82.91AE9.34,(85.50AE13.72) vs (84.68AE10.28) g,(79.61AE12.57) vs (78.13AE11.18) mmHg and (38.38AE30.67)% vs (37.70AE28.63)%,(46.80AE31.75)% vs (46.19AE30.35)%,all P>0.05)].The T/p ratio was no significant difference between two groups[(0.69AE0.11)/(0.68AE0.13) vs (0.70AE0.13)/ (0.68AE0.32),P>0.05].No serious side effects were observed in two groups. Conclusion: (1)The symptoms of EH can be relieved obviously by TCM or L-amlodipine besylate. (2) TCM can reduce 24hSBP,dSBP and nSBP and can not reduce 24hDBP,dDBP and nDBP. (3) There are mult-aspect advantages of symptomatic improvement,SBP dropping,lesser side effective that in the patients by the therapy of combining tianma gouteng decoction with lamlodipine besylate.This is a new way to treat hypertension by combination therapy.

Univ Kragujevac, Feb 1, 2014

In the present paper we exactly solve the distributed parameter stochastic model of the heterogen... more In the present paper we exactly solve the distributed parameter stochastic model of the heterogeneous catalytic reaction 2A + B 2 → 2AB and calculate the average number of reactive steps necessary to deactivate the lattice first,< t >. Results are compared with Monte Carlo simulations. < t > shows a nonmonotonic behavior with the sticking coefficient probability s and the desorption probability p d , reaching a maximum value that depends on s, p d and the lattice size N .

Physical Review E, 2021

In this work we study the fractal properties of diffusion-limited aggregation (DLA) clusters grow... more In this work we study the fractal properties of diffusion-limited aggregation (DLA) clusters grown on spherical surfaces. Diffusion-limited aggregation clusters, or DLA trees, are highly branched fractal clusters formed by the adhesion of particles. In two-dimensional media, DLA clusters have a fractal dimension D f = 1.70 in the continuous limit. In some physical systems, the existence of characteristic lengths leads us to model them as discrete systems. Such characteristic lengths may result also from limitations in measuring instruments, for example, the resolution of biomedical imaging systems. We simulate clusters for different particle sizes and examine the influence of discretization by exploring the systems in terms of the relationship between the particle size r and the radius of the sphere R. We also study the effect of stereographic projection on the fractal properties of DLA clusters. Both discretization and projection alter the fractal dimension of DLA clusters grown on curved surfaces and must be considered in the interpretation of photographic biomedical images.

Chemical Physics Letters, 2022

Heart rate variability (HRV) is mainly controlled by the autonomic nervous system (ANS) interacti... more Heart rate variability (HRV) is mainly controlled by the autonomic nervous system (ANS) interacting with receptors on the sinoatrial node (SAN). HRV is influenced by many several factors such as chemical, hormonal and neural modulations, circadian changes, exercise, emotions, posture, and preload. The heart rate adaptation to changing factors is carried out by the activity of a variety of regulatory subsystems and results in a complex linear and non- linear time behaviour, which changes with age, gender and pathological conditions. Many studies explore an age range of 1-99 years. This study focused on the development of a database of long-term time series of healthy volunteers aged between 1 month and 55 years.

In this work we present a study on the methane oxidation reaction on Cr2O3 in the presence of sul... more In this work we present a study on the methane oxidation reaction on Cr2O3 in the presence of sulfur dioxide using both infrared spectroscopy and simulations based on the density functional theory. The purpose of the work is to know the reasons why sulfur dioxide decreases the activation energy of the methane oxidation reaction. We found that sulfur dioxide promotes oxygen dissociation through the formation of sulfite species. Dissociated oxygen favors the dehydrogenation of methane, the formation of methoxy species, formaldehyde, dioxymethylene, and methanol.

En el presente trabajo se estudian las estructuras y geometrias moleculares del CH4 , SO2 y O2 ad... more En el presente trabajo se estudian las estructuras y geometrias moleculares del CH4 , SO2 y O2 adsorbidos sobre la superficie de Cr2O3 (0001). Mediante calculos computacionales basados en la Teoria Funcional de la Densidad (DFT) analizamos los sitios mas aptos para llevar a cabo la adsorcion de cada una de las moleculas mencionadas, asi como la influencia de de cada especie sobre la adsorcion y disociacion de las otras. Los resultados permiten comprender la activacion que produce la presencia de SO2 de la superficie de Cr2O3 (0001) para la oxidacion de CH4 , como fue verificado experimentalmente

espanolEn el presente trabajo se describen las caracteristicas fisicoquimicas de los compuestos F... more espanolEn el presente trabajo se describen las caracteristicas fisicoquimicas de los compuestos Flavonoides con mayor grado de estudio hasta la actualidad, y su aporte a la medicina tradicional y natural, junto con sus aplicaciones en el campo de la industria alimenticia. Los principales objetivos del mismo son, por un lado, proveer informacion fisicoquimica basica sobre las estructuras moleculares de los diferentes tipos con mayores aplicaciones industriales y medicinales hasta el presente, y por otro, relacionar las propiedades naturales de los alimentos que los contienen con los beneficios a la salud humana. EnglishIn this article, we describe the physicochemical characteristics of those flavonoid compounds which have been more deeply studied up to the present. We also analyze their contribution to traditional and natural medicine, together with their applications in food industry. The main objectives are, on the one hand, to provide basic physicochemical information about the mo...

Anales AFA, 2021

In this work we perform a theoretical study of dehydrogenation process of CH4 on O2– in both mole... more In this work we perform a theoretical study of dehydrogenation process of CH4 on O2– in both molecular and dissociative states - previously adsorbed on Cr2O3(0001). Calculations are based on Density Functional Theory (DFT). The results show the methanol formation form the adsorption of CH4 on O2 in dissociative state with a formationenergy5:14 eV. Also formaldehyde was formed by the reaction of CH2with molecular O2(Eads=6:09 eV) and dioxymethylene by the reaction of CH2with O2 previously adsorbed in dissociative state on Cr2O3(0001), withEads=8:17 eV. Finally, the vibrational modes found by DFT for each of the species were compared, which are in good agreement with those of reference bibliography. This allows us to support the values found both by technical calculations and by experimental methods.

MATCH Communications in Mathematical and in Computer Chemistry, 2021

In the present paper we extend the exact solution previously obtained for the heterogeneous catal... more In the present paper we extend the exact solution previously obtained for the heterogeneous catalytic reaction 2A + B2 → 2AB on small domains, to arbitrary lattice sizes () and calculate the average number of reactive steps necessary to poison the lattice first, . We determine as a function of through Monte Carlo simulations previously contrasted with the exact solution in lattices. We show that follows a power law with , without appreciable transient behaviors, and a scale factor () dependent on the two parameters of the model, the sticking coefficient probability and the desorption probability . The dependence of on both and is determined.

La emisión de dióxido de azufre por chimeneas industriales constituye una de las principales prob... more La emisión de dióxido de azufre por chimeneas industriales constituye una de las principales problemáticas ambientales, con las consecuencias ya conocidas de problemas para la salud de la población y con efectos nocivos como la lluvia ácida. En las chimeneas industriales, la reducción del SO2 ocurre por reacción con CH4, a la vez que este último es oxidado a CO2. La reacción completa ocurre en presencia del oxígeno atmosférico. Esta conversión es de gran importancia a nivel ambiental debido a que cada molécula de CH4 contamina como si se emitieran 21 moléculas de CO2 a la atmósfera (por lo tanto, al emitir CO2 en su lugar, se provoca un efecto contaminante 21 veces menor). El objetivo del presente trabajo de tesis doctoral fue el estudio del comportamiento de adsorción y reducción catalítica de SO2 sobre Cr2O3/Al2O3 en presencia de CH4 y O2 a altas temperaturas, a nivel experimental y teórico. Durante este trabajo, se variaron condiciones experimentales como las proporciones de los ...

IEEE Transactions on Dielectrics and Electrical Insulation, 2016

We report the results of electrical treeing tests carried out on a range of silicone dielectric g... more We report the results of electrical treeing tests carried out on a range of silicone dielectric gel samples made by varying the ratio of the same two components used for cross-linking a commercial silicone gel. These samples range from liquids to elastomers via two-phase gels. The extent of the curing is followed by means of FTIR spectroscopy and the samples are characterized through their dynamical mechanical properties. It is shown that the gel samples exhibit treeing behavior that includes features typical of both liquids and solids. A filamentary structure is produced that has permanence together with attached bubbles that self-heal locally during treeing, although differences in detail were found depending on the degree of curing. Removal of the treeing voltage allows a more substantial self-healing to occur. This behavior is discussed in terms of the two-phase liquid-solid nature of the silicone gels.

2015 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), 2015

Electrical treeing in silicone polymers has been investigated using a typical pin-plane geometry.... more Electrical treeing in silicone polymers has been investigated using a typical pin-plane geometry. The purpose of this work was to investigate the effect of ac field frequency upon the structure of treeing damage in a range of silicone dielectric materials. The liquid components were cured using different crosslinking ratios and hence both gels and elastomers were formed possessing a range of mechanical stiffness. These materials were characterized mechanically with an AR-G2 Rheometer. The results suggest that there is a clear dependence of the tree fractal dimension upon the applied ac voltage frequency and the sample's microstructure as characterized by oscillating rheometry.