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Papers by Carlos Perez Hernandez

Clinica Chimica Acta, 2008

It has been suggested that the incidence of coronary restenosis after a percutaneous coronary int... more It has been suggested that the incidence of coronary restenosis after a percutaneous coronary intervention is much higher in patients with a 287-bp alu repeat sequence within intron 16 of the angiotensin-I-converting enzyme (ACE) gene (deletion allele) than in others, but published studies are conflicting. The presence (insertion) or absence (deletion) of a 287-bp alu repeat sequence within intron 16 of the ACE gene (I/D polymorphism) was analyzed by polymerase chain reaction in a group of 168 patients with coronary artery disease who underwent coronary artery stenting. Basal and procedure coronary angiographies were analyzed searching for angiographic predictors of restenosis and follow-up angiography was analyzed looking for binary restenosis. Distribution of angiotensin converting enzyme I/D polymorphisms was similar in patients with and without restenosis. Similar results were observed when the analysis was made considering the type of stent implanted. On the other hand, the whole group of coronary artery disease patients showed increased frequencies of the D allele (p=0.00001, OR=2.17, 95% CI=1.49-3.16) and ID genotype (p=0.0002, OR=2.58, 95%CI=1.49-4.47) when compared to healthy controls. Genetic variations of the ACE gene could be a genetic factor related to coronary artery disease in the Mexican mixed racial ancestry individuals, but do not support its role as a risk factor for developing restenosis after coronary stenting.

This chapter describes a new bilateral control method of teleoperation systems. This method is ba... more This chapter describes a new bilateral control method of teleoperation systems. This method is based on the state space formulation and it can be applied to any teleoperation system where the master and the slave would be represented by nth-order linear differential equations. The control system allows that the slave manipulator follows the master. The tracking is achieved by state convergence between the master and the slave. The method is able also to establish the desired dynamics of this convergence and the dynamics of the slave manipulator. Furthermore a simple design procedure is provided to obtain the control system gains. The advantage of this design procedure is that it is only necessary to solve a set of equations to calculate the control system gains. The control by state convergence can be also applied to teleoperation systems with communication time delay. In this case, the Taylor expansion is used to approximate the time delay. The state convergence allows that the slave manipulator follows the master in spite of the time delay in the communication channel. Experimental results with a teleoperation system of one DoF are presented to verify the control method.

In this work, the measurements done, by way of digital holography, of auto-induced mechanical osc... more In this work, the measurements done, by way of digital holography, of auto-induced mechanical oscillations assumed by signals of frequency near to the first natural modal of resonance, are reported. Using a high speed digital camera, the study of a rectangular membrane under external excitation of a very low mechanical amplitude level, is done. The optical technique of high temporal and spatial resolution allows the acquisition and processing of data coming from thousands of acquired images with a relation of 5000 frames per second.

A study to evaluate the effect of molecular speciation considering methodologies to assign partia... more A study to evaluate the effect of molecular speciation considering methodologies to assign partial charges and conformational search processes for a docking test was made with mangiferin (MGF). This compound was selected as a model to explore speciation effects on drug design due to the speciation studies previously performed, and because it is a bioconjugate containing carbohydrate and polyphenolic xanthonoid groups, both moieties important as potential-drug candidates. PEOE (Partial Equalization of Orbital Electronegativity) resulted the best method to assign partial charges, with a good compromise between precision and computational cost, among different Classical Molecular Force Fields and Quantum Mechanics methods that were compared with Density Functional Theory calculations as the reference methodology. The number of conformations in energy minima showed to be extremely dependent upon partial charge assignation, as well as their geometry. In docking simulations of MGF on albumin drug-site 1, it was showed the relevance of choosing the properly expected chemical species for the pH value of interest since neutral MGF or deprotonated at the hydroxyl group on position 1 results in orientations significantly different from those predicted for the species deprotonated at the hydroxyl group on position 6, which is the predominant deprotonation site in accordance with the speciation study. The first two species present a tendency to expose the carbohydrate region to solvent occupying the same region in the binding site, while the molecule deprotonated in position 6 exhibits a preference for a different region of the site with its xanthonoid moiety exposed. Carbohydrate-polyphenol bioconjugates, such as MGF combine two types of bioactive molecules being both important as leaders for drug design. . siendo ambas partes constituyentes de moléculas bioactivas hace que nuestra molécula en estudio sea un buen caso modelo para la búsqueda de compuestos líder en el diseño de fármacos. Palabras clave: Xantonoides, búsqueda conformacional, reconocimiento molecular, diseño de fármacos, especiación química.

Optics and Lasers in Engineering, 2011

High speed digital holographic interferometry Optical metrology Self-induced oscillations a b s t... more High speed digital holographic interferometry Optical metrology Self-induced oscillations a b s t r a c t High speed digital holographic interferometry is used to measure the self-induced mechanical oscillations produced by frequency signals near the first natural resonance mode of a rectangular polyester membrane. The external excitation produces very low mechanical amplitude levels in the membrane. This non-invasive optical technique has high temporal and spatial resolution allowing large data acquisition and hence allowing the processing of thousands of recorded images acquired in a CMOS camera set at 5000 frames per second (fps).

... Oscar Pérez-Hernández, Carlos Cecilio Góngora-Canul, Ex-alumnos del Depto. de ... Los autores... more ... Oscar Pérez-Hernández, Carlos Cecilio Góngora-Canul, Ex-alumnos del Depto. de ... Los autores expresan su agradecimiento a Oswaldo Pech y Juan Canché, por el apoyo brindado en campo, ya Ricardo Balam por la ayuda en la detección de los fitoplasmas por PCR. ...

Clinical Nutrition, 2010

s u m m a r y Different types of dietary fiber can be distinguished considering their rate of fer... more s u m m a r y Different types of dietary fiber can be distinguished considering their rate of fermentability, thus determining the location of the large intestine where they exert their beneficial effect. Their combination could be interesting to obtain health-promoting effects throughout the entire colon. The aim of the present study was to evaluate the synergistic effect of two dietary fibers with different fermentation patterns, fructooligosaccharides (FOS) (Beneo Ò -95) and resistant starch (Fibersol Ò -2), after their administration to healthy rats or in trinitrobenzenesulphonic acid-(TNBS) colitic rats, with an altered colonic immune response. In healthy rats, the administration of the combination of FOS and resistant starch induced changes in the intestinal microbiota, by increasing lactobacilli and bifidobacteria in caecum and colonic contents. Furthermore, its administration up-regulated the expression of the trefoil factor-3 and MUC-2 in comparison with untreated rats, thus improving the intestinal barrier function. The beneficial effects observed with this combination were confirmed in the TBNS model of rat colitis, since it was able to exert intestinal anti-inflammatory effect, associated with an increase of protective bacteria and up-regulation of epithelial defense mechanisms. In conclusion, the combination of two different dietary fibers may result in a synergistic prebiotic effect, and may confer greater health benefits to the host.

Para llevar a cabo éste proyecto se deben realizar una serie de actividades las cuales van a invo... more Para llevar a cabo éste proyecto se deben realizar una serie de actividades las cuales van a involucrar a todos los estudiantes de la sede AguaBonita con el fin de practicar y vivenciar algunos valores que son fundamentales para mejorar la convivencia a nivel escolar, familiar y social. * Establecer normas para el comportamiento del grupo y, cuando sea necesario, realizar discusiones disciplinarias cuando se infringen éstas. * Planificar desde la intencionalidad didáctica el enriquecimiento de distintas propuestas.

Clinica Chimica Acta, 2008

It has been suggested that the incidence of coronary restenosis after a percutaneous coronary int... more It has been suggested that the incidence of coronary restenosis after a percutaneous coronary intervention is much higher in patients with a 287-bp alu repeat sequence within intron 16 of the angiotensin-I-converting enzyme (ACE) gene (deletion allele) than in others, but published studies are conflicting. The presence (insertion) or absence (deletion) of a 287-bp alu repeat sequence within intron 16 of the ACE gene (I/D polymorphism) was analyzed by polymerase chain reaction in a group of 168 patients with coronary artery disease who underwent coronary artery stenting. Basal and procedure coronary angiographies were analyzed searching for angiographic predictors of restenosis and follow-up angiography was analyzed looking for binary restenosis. Distribution of angiotensin converting enzyme I/D polymorphisms was similar in patients with and without restenosis. Similar results were observed when the analysis was made considering the type of stent implanted. On the other hand, the whole group of coronary artery disease patients showed increased frequencies of the D allele (p=0.00001, OR=2.17, 95% CI=1.49-3.16) and ID genotype (p=0.0002, OR=2.58, 95%CI=1.49-4.47) when compared to healthy controls. Genetic variations of the ACE gene could be a genetic factor related to coronary artery disease in the Mexican mixed racial ancestry individuals, but do not support its role as a risk factor for developing restenosis after coronary stenting.

This chapter describes a new bilateral control method of teleoperation systems. This method is ba... more This chapter describes a new bilateral control method of teleoperation systems. This method is based on the state space formulation and it can be applied to any teleoperation system where the master and the slave would be represented by nth-order linear differential equations. The control system allows that the slave manipulator follows the master. The tracking is achieved by state convergence between the master and the slave. The method is able also to establish the desired dynamics of this convergence and the dynamics of the slave manipulator. Furthermore a simple design procedure is provided to obtain the control system gains. The advantage of this design procedure is that it is only necessary to solve a set of equations to calculate the control system gains. The control by state convergence can be also applied to teleoperation systems with communication time delay. In this case, the Taylor expansion is used to approximate the time delay. The state convergence allows that the slave manipulator follows the master in spite of the time delay in the communication channel. Experimental results with a teleoperation system of one DoF are presented to verify the control method.

In this work, the measurements done, by way of digital holography, of auto-induced mechanical osc... more In this work, the measurements done, by way of digital holography, of auto-induced mechanical oscillations assumed by signals of frequency near to the first natural modal of resonance, are reported. Using a high speed digital camera, the study of a rectangular membrane under external excitation of a very low mechanical amplitude level, is done. The optical technique of high temporal and spatial resolution allows the acquisition and processing of data coming from thousands of acquired images with a relation of 5000 frames per second.

A study to evaluate the effect of molecular speciation considering methodologies to assign partia... more A study to evaluate the effect of molecular speciation considering methodologies to assign partial charges and conformational search processes for a docking test was made with mangiferin (MGF). This compound was selected as a model to explore speciation effects on drug design due to the speciation studies previously performed, and because it is a bioconjugate containing carbohydrate and polyphenolic xanthonoid groups, both moieties important as potential-drug candidates. PEOE (Partial Equalization of Orbital Electronegativity) resulted the best method to assign partial charges, with a good compromise between precision and computational cost, among different Classical Molecular Force Fields and Quantum Mechanics methods that were compared with Density Functional Theory calculations as the reference methodology. The number of conformations in energy minima showed to be extremely dependent upon partial charge assignation, as well as their geometry. In docking simulations of MGF on albumin drug-site 1, it was showed the relevance of choosing the properly expected chemical species for the pH value of interest since neutral MGF or deprotonated at the hydroxyl group on position 1 results in orientations significantly different from those predicted for the species deprotonated at the hydroxyl group on position 6, which is the predominant deprotonation site in accordance with the speciation study. The first two species present a tendency to expose the carbohydrate region to solvent occupying the same region in the binding site, while the molecule deprotonated in position 6 exhibits a preference for a different region of the site with its xanthonoid moiety exposed. Carbohydrate-polyphenol bioconjugates, such as MGF combine two types of bioactive molecules being both important as leaders for drug design. . siendo ambas partes constituyentes de moléculas bioactivas hace que nuestra molécula en estudio sea un buen caso modelo para la búsqueda de compuestos líder en el diseño de fármacos. Palabras clave: Xantonoides, búsqueda conformacional, reconocimiento molecular, diseño de fármacos, especiación química.

Optics and Lasers in Engineering, 2011

High speed digital holographic interferometry Optical metrology Self-induced oscillations a b s t... more High speed digital holographic interferometry Optical metrology Self-induced oscillations a b s t r a c t High speed digital holographic interferometry is used to measure the self-induced mechanical oscillations produced by frequency signals near the first natural resonance mode of a rectangular polyester membrane. The external excitation produces very low mechanical amplitude levels in the membrane. This non-invasive optical technique has high temporal and spatial resolution allowing large data acquisition and hence allowing the processing of thousands of recorded images acquired in a CMOS camera set at 5000 frames per second (fps).

... Oscar Pérez-Hernández, Carlos Cecilio Góngora-Canul, Ex-alumnos del Depto. de ... Los autores... more ... Oscar Pérez-Hernández, Carlos Cecilio Góngora-Canul, Ex-alumnos del Depto. de ... Los autores expresan su agradecimiento a Oswaldo Pech y Juan Canché, por el apoyo brindado en campo, ya Ricardo Balam por la ayuda en la detección de los fitoplasmas por PCR. ...

Clinical Nutrition, 2010

s u m m a r y Different types of dietary fiber can be distinguished considering their rate of fer... more s u m m a r y Different types of dietary fiber can be distinguished considering their rate of fermentability, thus determining the location of the large intestine where they exert their beneficial effect. Their combination could be interesting to obtain health-promoting effects throughout the entire colon. The aim of the present study was to evaluate the synergistic effect of two dietary fibers with different fermentation patterns, fructooligosaccharides (FOS) (Beneo Ò -95) and resistant starch (Fibersol Ò -2), after their administration to healthy rats or in trinitrobenzenesulphonic acid-(TNBS) colitic rats, with an altered colonic immune response. In healthy rats, the administration of the combination of FOS and resistant starch induced changes in the intestinal microbiota, by increasing lactobacilli and bifidobacteria in caecum and colonic contents. Furthermore, its administration up-regulated the expression of the trefoil factor-3 and MUC-2 in comparison with untreated rats, thus improving the intestinal barrier function. The beneficial effects observed with this combination were confirmed in the TBNS model of rat colitis, since it was able to exert intestinal anti-inflammatory effect, associated with an increase of protective bacteria and up-regulation of epithelial defense mechanisms. In conclusion, the combination of two different dietary fibers may result in a synergistic prebiotic effect, and may confer greater health benefits to the host.

Para llevar a cabo éste proyecto se deben realizar una serie de actividades las cuales van a invo... more Para llevar a cabo éste proyecto se deben realizar una serie de actividades las cuales van a involucrar a todos los estudiantes de la sede AguaBonita con el fin de practicar y vivenciar algunos valores que son fundamentales para mejorar la convivencia a nivel escolar, familiar y social. * Establecer normas para el comportamiento del grupo y, cuando sea necesario, realizar discusiones disciplinarias cuando se infringen éstas. * Planificar desde la intencionalidad didáctica el enriquecimiento de distintas propuestas.