• Platelets contribute to hemostasis, thrombosis, and allergic airway inflammation via Munc13-4-dependent secretion

      Cárdenas Cantú, Eduardo Israel (Instituto Tecnológico y de Estudios Superiores de MonterreyInstituto Tecnológico y de Estudios Superiores de Monterrey, 2018-11-01)
      With over 200 million affected individuals, asthma is the most common chronic respiratory disease in the world. One old observation that begs an explanation is the relationship between platelets, their activation, and the manifestations of asthma. Although platelets are mostly known for their crucial role in coagulation, a growing body of evidence indicates they also participate in asthma. Platelets store in their alpha, dense, and lysosomal granules multiple mediators; most of which are required for effective coagulation, but some have been shown to affect the main pathophysiologic mechanisms in asthma: airway hyperresponsiveness (AHR), migration and activation of eosinophils, and alterations in the airway epithelium. These granule contents are released upon activation via exocytosis, which depends on SNARE proteins and regulatory elements, such as Munc13 proteins. Because platelets express multiple isoforms of these proteins, it is possible that the exocytic components mediating the release of each type of platelet granule are unique. We proposed that by identifying the exocytic components associated with a single type of platelet granule, we could impair its release and study in vivo its role in asthma. We hypothesized that selective impairment of specific platelet granule subpopulations would alter the asthmatic response. With this in mind, we first identified the Munc13 paralogs expressed in platelets, and used loss-of-function models to test how each Munc13 protein participated in exocytosis of alpha, dense, and lysosomal granules. We then studied how the lack of a specific Munc13 protein affected platelet function in vitro and in vivo, using animal models of thrombosis and hemostasis. Finally, we studied platelet-specific knockout (KO) mice in an asthma model to test our hypothesis. We found that genetic deletion of Munc13-4 mostly impaired platelet dense granule release, which translated into a strong hemostatic defect, and that platelet-specific Munc13-4 KO mice had a reduction in airway hyperresponsiveness and eosinophilic inflammation in a model of asthma. Taken together, our results indicate that Munc13-4-dependent platelet secretion plays essential roles in hemostasis, thrombosis, and asthma.
    • Carbon policy in presence of a consumer-friendly firm

      Kalashnikov, Viacheslav; Kalashnykova, Nataliya; García Martínez, Arturo; Smith Cornejo, Neale Ricardo; Ángel Bello Acosta, Francisco Román; Güemes Castorena, David (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-07)
      This dissertation studies the implications of the emergence of a consumer-friendly firm in a duopolistic polluting industry when the regulator can or not commit credibly to an environmental instrument, such as an emission tax or a tradable permits policy. The welfare and environmental consequences are examined. It also investigates the conditions under which one of these instruments is superior to the other. In the second chapter, the study considers a Cournot duopoly model with a consumer-friendly firm and analyzes the interplay between the strategic choice of abatement technology and the timing of government’s commitment to the environmental tax policy. We show that the optimal emission tax under committed policy regime is always higher than that under non-committed one, but both taxes can be higher than marginal environmental damage when the consumer-friendliness is high enough. We also show that the emergence of a consumer-friendly firm might yield better outcomes to both welfare and environmental quality without the commitment to the environmental policy. The third chapter considers the timing of environmental policies with a consumerfriendly firm having abatement technology and compares two market-based regulatory instruments, tradable permits, and emission tax regulations. When the government can credibly commit its policy, we show that the equilibrium outcomes under both policies are equivalent in terms of permits price and tax rate. Under the non- committed policy, however, the equivalence breaks down because firms have opposite incentives to induce time-consistent policy to be adjusted ex-post. In particular, compared to pre-committed government, firms abate less emission to induce higher emission quotas under the permits policy while a consumer-friendly firm abates more emissions to reduce tax rate under the tax policy. Finally, we show that tax policy will result in higher welfare and lower environmental damage unless the concern on consumer surplus is considerable.
    • Tailored optical fields and their applications in quantum information processing

      Hernández Aranda, Raúl Ignacio; Korand, Thomas; Pérez García, Benjamín de Jesús; López Mago, Dorilián; Rodríguez Mesagosa, Rodolfo; Gutiérrez Vega, Julio César (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15)
      A set of experimental techniques to digitally shape an optical beam are presented. In particular, we show how to digitally study the interference phenomena in different geometries and observables. We also present a novel way of generating arbitrary vector beams and controlling the spatial coherence of a classical beam using Spatial Light Modulators. These type of manipulations are further employed to control and experimentally implement quantum algorithms, more precisely the Deutsch, Deutsch-Jozsa and Grover`s search algorithms.
    • Oligopoly studies: on the interaction of private firms with homogeneous and heterogeneous objectives

      Kalashnikov, Viacheslav; Kalashnykova, Nataliya; Leal Coronado, Mariel Adriana; David Güemes Castorena; Smith Cornejo, Neale Ricardo; Bello Acosta, Francisco Román Ángel (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-14)
      Two oligopoly studies compose this thesis. The first study considers that firms have the homogenous objective of maximizing their profits. The second one contemplates the presence of a private firm with a different objective, a consumer friendly firm. In detail, in the second chapter, the effects of uniting two separated markets each monopolized initially by a producer into a globalized duopoly market are studied. A linear inverse demand with cap price and quadratic cost functions is considered. After globalization, the Consistent Conjectural Variations Equilibrium of the duopoly game is found. Unlike the Cournot Equilibrium, complete symmetry (same cost function’s parameters of both firms) does not represent the strongest coincident profit degradation. When both firms are low-marginal cost firms, it is found that the firm with a technical advantage over her rival has a better ratio and as the rival becomes weaker, this is, as the slope of the rival’s marginal cost function increases, the profit ratio improves. In the third chapter, the study considers a Cournot duopoly model with a consumer-friendly firm and analyzes the interplay between the strategic choice of abatement technology and the timing of government’s commitment to the environmental tax policy. It is shown that the optimal emission tax under committed policy regime is always higher than that under non-committed one, but both taxes can be higher than marginal environmental damage when the consumerfriendliness is high enough. It is also shown that the emergence of a consumer friendly firm might yield better outcomes to both welfare and environmental quality without the commitment to the environmental policy.
    • Potencial de reducción de emisiones de gases de efecto invernadero en la cadena de producción de ganado bovino en el estado de Nuevo León, México

      Manzano Caramillo, Mario Guadalupe; Carbajal Morón, Nallely Alejandrina; Lozáno García, Diego Fabían; Díaz Solís, Heriberto; Armienta Trejo, Gilberto; Hernández Javalera, Iliana Isabel (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-14)
      El objetivo de esta investigación fue realizar un análisis de las fuentes y sumideros de emisiones de Gases de Efecto Invernadero dentro de la cadena de producción de ganado bovino. Se analiza la situación en México respecto a la importancia del sector ganadero en la contribución a las emisiones a nivel nacional y a nivel estatal. Posteriormente, se evalúan cuatro casos de estudio (extensivos y semi-intensivos) con la finalidad de representar las diversas prácticas del sector en el norte de México, y encontrar las principales fuentes y sumideros de carbono dentro de la actividad productiva. Por último se realizan dos escenarios a futuro para el estado de Nuevo León, acerca de que efecto tendrían en la disminución de emisiones de gases de efecto invernadero la implementación de ciertas prácticas en todas las unidades productivas del estado. Los balances de carbono de los distintos sistemas demostraron que teniendo un manejo adecuado de los pastizales e implementando prácticas de agroforesteria, los sistemas extensivos tienen un gran potencial de ser sumideros de carbono. Adicional a esto, de acuerdo a los resultados obtenidos, se considera necesario tanto en los sistemas semi-intensivos como en los extensivos, mejorar la alimentación del ganado y llevar a cabo un manejo adecuado de los residuos para garantizar un balance de misiones de CO2eq positivo. De implementarse estás mejores prácticas en las unidades productivas del estado de Nuevo León, pudieran mitigarse hasta un 80% de las emisiones de GEI del sector AFOLU del estado de Nuevo León. Los resultados de esta investigación son un referente para comprender la capacidad de mitigación de emisiones de GEI de los sistemas ganaderos y sin duda son un parámetro de referencia útil para los tomadores de decisiones, pues contribuirá a enfocar recursos y esfuerzos a proyectos que aseguren la disminución de emisiones.
    • Self-Assembly behavior of amphiphilic janus dendrimers in water: a combined experimental and coarse-grained molecular dynamics simulation approach

      Valencia Gallegos, Jesús Ángel; Videa Vargas, Marcelo Fernando; Elizondo García, Mariana Estefanía; Gutiérrez Uribe, Janet Alejandra; González Nilo, Fernando Danilo; Cortéz Ramírez, Jorge (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-14)
      Amphiphilic Janus dendrimers (JDs) are repetitively branched molecules with hydrophilic and hydrophobic components that self-assemble in water to form a variety of morphologies, including vesicles analogous to liposomes with potential pharmaceutical and medical application. To date, the self-assembly of JDs has not been fully investigated thus it is important to gain insight into its mechanism and dependence on JDs’ molecular structure. In this study, a series of amphiphilic JDs with variations in their core and branching pattern was synthesized and its aggregation behavior in water was evaluated using experimental and computational methods. JDs were obtained from 2,2-bis(hydroxymethyl)propionic acid, myristic acid and different glycols. Dispersions of JDs in water were carried out using the thin-film hydration, solvent injection methods and by microfluidics, using double emulsion drops with ultrathin shells as templates. Furthermore, a coarse-grained molecular dynamics (CG-MD) simulation was performed to study the mechanism of JDs aggregation. The resulting assemblies were characterized by optical microscopy, dynamic light scattering, confocal microscopy, and atomic force microscopy. The obtaining of assemblies in water with no interdigitated bilayers was confirmed by the experimental characterization and CG-MD simulation for one of the dendrimers. Assemblies with dendrimersome characteristics were obtained using the solvent injection method. Also, monodisperse nanometric assemblies were obtained by this method. The use of microfluidics enables the production of giant dendrimersomes from highly hydrophobic JDs, even when the dendrimers did not form vesicles using the thin-film hydration method. The results of this study establish a relationship between the molecular structure of the JDs and the properties of its aggregates in water. These results could be relevant for the design of novel JDs with tailored assemblies suitable for drug delivery systems. In addition, this study offers an approach to produce dendrimersomes in a more controlled way.
    • Nutraceutical properties of isolated starch, phytochemical compounds and bioactive peptides from pigmented chickpea cultivars influenced by cooking or germination process.

      Serna Saldívar, Sergio O.; Gutiérrez Uribe, Janet Alejandra; Milán Noris, Ada Keila; Jacobo Velázquez, Daniel A.; Santacruz López, Yolanda Arlette; Reyes Moreno, Cuauhtémoc Reyes Moreno (2017-12-14)
      Chickpea (Cicer arietinum L.) is the third most consumed pulse worldwide and a potential functional ingredient due to its nutritious composition and bioactive compounds. The aim of this investigation was to evaluate the potential of ten pigmented chickpea cultivars as ingredients in functional foods using cooking or germination to enhance bioactive compounds with health effect. The investigation was performed in five steps in order to evaluate the potential of ten chickpea cultivars differing in seed coat color (black, brown, green, red and cream). The first approach was to evaluate chickpea flours on the techno-functionality, chemical composition and nutritional properties related to starch and protein. The colored chickpeas flours showed higher content of bioactive compounds as total phenolics (TPC), β-glucans, resistant starch and higher protein digestibility corrected amino acid score (PDCAAS) compared with the commercial chickpea Blanco Sinaloa (cream seed coat). The limiting amino acids in chickpea flours were Trp, Thr and Met+Cys, whereas PDCAAS ranged from 0.59 to 0.82. Correlation analysis showed a possible interaction between TPC and starch which influenced thermal properties and starch digestion. The principal component analysis (PCA) showed several differences among the chemical compositions, starch digestions and seed protein qualities. Moreover, starch is the major component of chickpea seeds; therefore the wet-milled chickpea starches were studied on physicochemical, functional and in vitro starch digestion properties. The yield of chickpea starches ranged from 19.22 to 30.06%; total starch and amylose contents in the starches varied from 87.14 to 96.02% and 25.05 to 35.26%, respectively. Gelatinization properties (DSC, RVA) showed large differences among starches. The rapidly digestible (RDS), slowly digestible (SDS) and resistant (RS) gelatinized starch fractions varied from 56.34 to 59.15%, 33.22 to 35.43% and 6.42 to 9.22%, respectively. The predicted glycemic indexes (pGI) of native and gelatinized chickpea starches ranged from 65.52 to 66.10 and 74.39 to 75.74, respectively. A close correlation among the viscosity characteristics of isolated starches and the starch digestion fractions were found after PCA analysis. The starches properties were not dependent of the seed coat coloration of the cultivars. Overall, the results suggest that the starches of the array of chickpeas studied may hold a potential for the development of functional foods especially due to its functional properties, medium glycemic index, high SDS and RS contents. Additionally, the fate of phytochemicals during cooking and germination was evaluated. The 10 chickpea cultivars were soaked and cooked for the phytochemical evaluation. The compounds were identified by HPLC-IT-MS and quantified by HPLC-UV-ELSD. In Milán-Noris, A.K. 7 the raw chickpea seeds, eleven compounds were identified among cultivars; soyasaponin βg (m/z 1068) and biochanin A (m/z 285) were the principal compounds found. The thermal process caused significant (p≤0.05) reduction in flavonoids content but only minor lost of total saponins content. Besides, the effect of the germination process on phytochemicals of four chickpea cultivars (black, cream, green and red) was evaluated. Chickpea cultivars were germinated during five day at 24ºC. Eight isoflavonoids and soyasaponin βg were identified in germinated chickpea cultivars. However, genotype showed a significant effect on the profile and content of isoflavonoids during germination process. Phytochemical content increased significantly during germination process in all chickpea cultivars. Lastly, the anti-inflammatory effects of peptides and isoflavonoids associated to the unabsorbed digestion of protein concentrates from cooked or germinated (G.ICC5613 and Blanco Sinaloa) chickpea cultivars were investigated. The simulated gastrointestinal digestion released isoflavonoids and peptides (<10 kda=""><10kDa) in coocked and germinated samples whit adequate capacity to reduce nitric oxide production in induced- LPS macrophages. In both cultivars, the germinated samples showed higher reduction in nitric oxide by phenolics and peptides fraction. The digest from ferminated Blanco Sinaloa showed anti-inflammatory effects exerted by phenolics (IC50 : 0.22 mg/mL) and peptides (IC50: 1.92 mg protein/mL). The major phenolics were biochanin-A and formononetin. The further purification of the most active fraction produced peptides from legumin and vicilin. This is the first report of anti-inflammatory peptides from processed chickpea released by simulated gastrointestinal digestion. Overall, the results suggest that pigmented chickpea cultivars of this study showed a great potential as functional ingredients.
    • Application of ultrasonic micro injection molding for manufacturing of UHMWPE microparts

      Zuñiga, Alez Elías; Hernández Ávila, Marcelo; Sánchez Sánchez, Xavier; Martínez Romero, Oscar; Siller Carillo, Héctor Rafael; Pallacios, Luis Manuel (2017-12-05)
      Ultrasonic micro injection molding was confirmed to be an efficient processing technique for the fabrication of a well-filled miniaturized dog-bone shaped specimen of ultra-high molecular weight polyethylene (UHMWPE). The influence of parameters such as mold temperature, plunger velocity profile, vibrational amplitude, shape of raw material, is analyzed using techniques such as the Design of Experiments, and a methodological proposal. The influence of four process parameters on the filling phase of the reduced-size cavity was then analyzed . It was established that it is possible to fabricate well-defined specimens when the highest ultrasonic amplitude is applied intermittently at specific intervals during the ultrasonic process to small compacted irregularly shaped UHMWPE samples and the mold temperature is set to 100 °C. GPC results showed a decrease in the molecular weight, which was the greatest when 100% of the ultrasonic amplitude was applied. The degree of crystallinity of the processed sample was increased because the reduction of the molecular weight. TGA showed that the thermal stability of UHMWPE fabricated by ultrasonic processing was not significantly influenced by the decrease in the molecular weight. FTIR spectra indicated oxidative degradation in three different regions of the processed UHMWPE specimen. Additionally, the band identified at the wavenumber 910 cm-1 indicated a chain scission phenomenon the polymer experienced during the ultrasonic processing
    • Development of SERS substrates for the characterization of cellular systems and the determination of molecules of interest

      Ornelas Soto, Nancy Edith; Aguilar Hernández, Iris Anahí; García García, Alejandra; Cárdenas Chávez, Diana Linda; Rodríguez Delgado, Melissa (2017-12-04)
      Raman spectroscopy is a powerful vibrational spectroscopy technique that provides useful information regarding the chemical composition of a sample. It is a label-free technique that can be successfully applied for both single analyte detection and the analysis of complex matrices. The only main limitation of Raman spectroscopy is the inherent low scattering efficiency. Surface Enhanced Raman Spectroscopy (SERS) is employed to overcome this limitation. SERS active structures are typically in the form of colloidal solutions, or as solid substrates with metallic nanostructures on the surface. The work included in this dissertation explores the development of SERS substrates for (a) the detection of a single molecule of interest, and (b) the analysis of cellular systems. For the detection of molecules of interest, two studies were carried out: In the first study, the ideal synthesis conditions of colloidal silver nanoparticles that rendered the highest SERS enhancement was explored via principal component analysis (PCA). The selected silver nanoparticles were used for the ultrasensitive detection of phenolic compounds in solution. The second work focused on the development of solid substrates, where gold nanoparticles were synthesized and immobilized on a carbon nanofibers matrix and enhancement capacity of the SERS substrate was evaluated with Rhodamine 110. The use of SERS for the analysis of biological systems was also explored. First, the effect of an oxidative agent (CdTe quantum dots) on the freshwater microalgae H. pluvialis was studied with SERS via colloidal gold nanoparticles. Mammalian cell lines were also analyzed; Colloidal concave gold nanocubes were synthesized and immobilized onto a solid substrate for SERS enhancement of HeLa cells, showing that solid SERS substrates are also suitable for cell analysis. Finally, radiation resistant and radiation sensitive murine leukemia sublines were characterized for the first time by normal Raman spectroscopy and SERS, with the aim of contributing the development of predictive radiosensitivity assays. SERS substrates in colloidal and solid form were developed, and successfully used for the label-free detection of analytes in solution and complex biological samples, showing the versatility of SERS and contributing to this growing multidisciplinary field.
    • Sliding mode control for doubly fed induction machine

      Pedro Ponce Cruz; Arturo Molina Gutiérrez; Villanueva Rosas, Iván Salvador; José Antonio Rosales Martínez; Juan Carlos Ramírez Martínez; Carlos Ernesto Ugalde Loo (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2017-12-01)
      The objective of this thesis is to provide robust control methods for Doubly Fed Induction Generator (DFIG) mainly used for wind energy conversion systems (WECS). The controller deals with the power electronic stage needed to control the electric machine. Due to the high sensibility of this machine against disturbances the systems requires an accurate controller that allows to follow the stator power regulation despite the presence of disturbances.       DFIG-based WECS are highly sensible to stator voltage perturbations because the stator is directly connected to the electric grid. The offered controller can regulate torque and reactive power even during low depth voltage dips by injecting negative sequence current without the necessity of sequence components separation of the rotor current.                  The proposed control system is based on Sliding-Mode Control (SMC),  offering a fast-dynamic response and providing insensitivity to matched and bounded disturbance/uncertainties. The naturally discontinuous control signals of SMC can be used for direct switching of power electronic devices avoiding modulation and making the control system simple and robust. Furthermore, the controller does not depend on electric machine's parameters and it is decoupled by means of reference frame orientation.                  The switching frequency is analyzed using a frequency-domain method known as Tsypkin's locus, therefore it is possible to calculate a hysteresis width which will maintain the switching frequency inside safe operational range preventing to exceed the maximum switching frequency of semiconductor devices.                  The dynamic response of the control system under balanced and unbalanced voltage faults is enhanced by the application of demagnetizing current for fast natural flux clearance. The demagnetizing current is supplied using the original controller by modifying the torque and reactive power references.                     The operation of the controller and the ideas presented in this thesis have been verified through simulations made in National Instruments\textsuperscript LabVIEW and Matlab Simulink.
    • Controlled drug delivery strategies: Advances on the synthesis and molecular dynamics of dendrimers, and optimization of liposomes preparation by Dual Asymmetric Centrifugation

      Valencia Gallegos, Jesús Ángel; Sampogna-Mireles, Diana; Guitiérrez Uribe, Janet Alejandra; Elizondo Martínez, Perla; Hernández Hernández, José Ascención; Aguilar Jimenéz, Oscar Alejandro (2017-12-01)
      In early phase of drug development, New Chemical Entities (NCEs) are used as highly active drugs, with limited availability, and high cost. This study presents two alternatives of drug delivery systems, site-specific dendrimers and liposomes, with potential use as carriers of highly active drugs like pristimerin. Advances in the synthesis of site-specific dendrimers with bis-MPA as branching precursor and three key building blocks are reported, including compounds with folic acid (FA) to provide selectivity to folate receptors of cancer cells, pristimerin as cancer drug model, and fluorescein isothiocyanate (FITC) as fluorescent dye for future evaluation as cancer treatment. Five different dendrimer syntheses were reported, differing on their nucleus (bis-MPA or ethylene glycol) and the linker of folic acid (PEG 3350 and triethylene glycol TEG). Different purification techniques, such as normal-phase and reverse-phase column chromatography, size exclusion chromaography, dialysis and ultrafiltration, were probed according to their chemical characteristics and solubility. Characterization was carried out by FT-IR, MALDITOF-MS and/or NMR. Theoretical evidence generated in this work supports that FA-PEG750 and FA-PEG3350 dendrimers can be applied to selectively carry drugs and interact with cancer cell receptors (FR-α). Another drug delivery carrier and a viable alternative to the use of dendrimers is liposomes. Liposomes are the most mature drug carriers for passive and active targeting commercially available in oncology and other disease treatments. Dual Asymmetric Centrifugation (DAC) is a novel, fast, simple, and reproducible method for liposomal formulation screening, it facilitates liposomes preparation, and favors small diameters (<120 nm) in a small scale, with high drug encapsulation (EE). An optimization of DAC parameters (type and volume of buffer, beads size, centrifugation speed and time) was done to obtain liposomes of 70-80 nm with high encapsulation efficiency (71%). Also, dialysis was the best method for liposomes purification in comparison to Zeba-Spin and Micro-Spin size-exclusion columns, and can be applied to other drug delivery systems, like dendrimers. Over all, site-specific dendrimers demand a meticulous control on their structure during synthesis. Their preparation is time consuming and analytically complex. Meanwhile, theoretical evidence supports their potential to selectively carry drugs and interact with cancer cell receptors. Meanwhile, liposomes are a faster, easier and versatile alternative as drug delivery carriers of highly toxic drugs.
    • Novel bioengineering strategies for the recovery and purification of PEGylated lysozyme conjugates: in situ ATPS and affinity chromatography

      Mejía, Luis (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2017-07-13)
      PEGylation is the modification of therapeutic proteins with polyethylene glycol (PEG) with the goal of improving their bioavailability and effectivity in the organism. During the PEGylation process, proteins with different degrees of PEGylation and positional isomers are generated. Numerous chromatographic and non-chromatographic techniques have been used for the purification of the adequate or most active conjugate. However, the obtained yields are still low, representing an interesting engineering challenge to address. Therefore, novel techniques to achieve this must be devised. In the present work, two strategies were explored: in situ aqueous two-phase systems (ATPS) and affinity chromatography. Aqueous two-phase systems (ATPS) are a promising alternative for recovering modified proteins but this technique has not been tested with complete PEGylation reactions. In this work, lysozyme PEGylation reactions were used as part of the phase-forming chemicals to form in situ ATPS. This was best achieved by adding a 4M ammonium sulphate in a 20 mM Tris-HCl pH 7.0 solution. The phases were separated and analyzed by monolithic chromatography and SDS-PAGE. Results indicate that PEGylated lysozymes (mono- and di-) are mainly fractionated to the top phase (56% and 100% respectively) while native lysozyme was found in the bottom phase (97.7%). On the other hand, PEG-modified and native lysozyme adsorption to Heparin Sepharose was described by Langmuir isotherms. The affinity of the conjugates decreased with the PEGylation degree with no significant binding of the reactive 20 kDa mPEG to the resin. A method in Heparin Affinity Chromatography (HAC) eluting with NaCl gradient was developed and optimized through Response Surface Methodology for the purification of mono-PEGylated lysozyme with a better yield, purity and productivity than other reported chromatographic modes. A formulated rate model could model and simulate the separation of mono-PEGylated and native lysozymes in HAC. Diverse mass transfer data were obtained from this simulation. Finally, as an antecedent to the generation of immunosorbents to purify PEGylated proteins, the immobilization conditions of antibodies on NHS Sepharose 4 Fast Flow were viii optimized with a factorial design. The antibody isotype showed effects on the coupling efficiency, being improved when isotype G was used. In conclusion, in situ ATPS and heparin affinity chromatography combined with optimization tools such as design of experiments, modelling and simulation represent new and never reported before techniques in the recovery and purification of PEGylated lysozyme with several advantages with respect to currently used methods.
    • Prediction of AR marker's position: A case of study using regression analysis with Machine Learning method

      Guedea Elizalde, Federico; Villegas Hernández, Yazmín Sarahí; Rodríguez González, Ciro Ángel; Smith Cornejo, Neale Ricardo; González Mendívil, Eduardo; Siller Carillo, Héctor Rafael (2017-05-15)
      In an automated assembly process with robotic assistance, it is used vision system, which is used to monitor or control the assembly process. In the assembly process, the vision system recognizes objects and estimates the position and orientation. Furthermore, the optical tracking information in manufacturing can provide valuable support and time saving for autonomous operations, but ill environment conditions prevent a better performance of vision systems. This thesis research presents a novel method for estimating object position under semi-controlled environment where lighting conditions change dynamically is proposed. This method incorporates machine learning and regression analysis that combines light measurement and an augmented reality (AR) system. Augmented Reality (AR) combines virtual objects with real environment. Furthermore, every AR application uses a video camera to capture an image including a marker in order to place a virtual object, which gives user an enriched environment. Using a tracking system to estimate the marker’s position with respect to the camera coordinate frame is needed to positioning a virtual object. Most research studies on tracking system for AR are under controlled environment. The problem is that tracking systems for markers are sensitive to variations in lighting conditions in the real environment. To solve this problem, a method is proposed to estimate better a marker position based on regression analysis, where lighting conditions are taken into account. The proposed approach improves the accuracy of the marker position estimation under different lighting conditions.
    • Development of a hybrid ejector-compressor refrigeration system with improved efficiency

      Gutiérrez Ortiz, Alejandro; ALEJANDRO GUTIERREZ ORTIZ;347162 (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2016-09-02)
      The present doctoral dissertation addresses the design of an ejector suitable for a thermally driven hybrid ejector-compressor cooling system; research was aimed at improving the performance of the ejector in terms of both critical backpressure and entrainment ratio. An ejector efficiency analysis is presented to establish a theoretical limit for the maximum achievable entrainment ratio of an ejector undergoing a fully reversible process without entropy generation; the main sources of irreversibility within the ejector are subsequently discussed. The shock circle model is implemented as a mean to predict the entrainment ratio for an ejector with a given set of nozzle and constant area section diameters; experimental results from the literature are presented and used to validate the model. A Computational Fluid Dynamics design exploration aimed at identifying the effects of the rest of the key geometrical parameters that are not covered by the mathematical model is also presented. In order to generalize the findings from this study for ejectors of different scales, the results are presented using non-dimensional parameters. The study showed that in order to guarantee a critical mode operation at the range of operating conditions suitable for a hybrid ejector-compressor cycle, only the constant area section or the nozzle throat diameters need to vary accordingly with the condenser backpressure. The optimum geometrical parameters found by the design exploration are used to propose an optimized ejector design, the Constant Rate of Momentum Change method is also implemented to generate a diffuser geometry that reduces one of the sources of entropy generation identified during the first stages of this research. The assessment of the performance increase for the proposed ejector is measured against a baseline design; the results showed that the new ejector outperforms the baseline in terms of both entrainment ratio and critical condenser backpressure. The thesis concludes with a study to quantify the thermal efficiency increase of a hybrid ejector-compressor system employing the proposed ejector, lastly, the design for a test stand to experimentally verify the findings of this research work is proposed.
    • Desarrollo de aplicaciones virtuales de entrenamiento médico incorporando dispositivos hápticos

      Ricárdez Vázquez, Eusebio; EUSEBIO RICARDEZ VAZQUEZ;348934 (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2016-09-02)
      En la actualidad los ambientes virtuales de aprendizaje son herramientas ampliamente utilizadas en el ámbito académico y están presentes en prácticamente todas las áreas del conocimiento. La medicina no es la excepción, inclusive es una de las áreas en las que los ambientes de simulación presentan grandes ventajas, al evitar que el aprendizaje sea en cadáveres o seres vivos. Se ha demostrado que un ambiente virtual es más eficaz cuando puede enviar al usuario sensaciones táctiles que permitan al usuario interactuar de forma más completa con el mismo. En este trabajo se desarrollan las técnicas necesarias para generar un ambiente virtual de entrenamiento médico que envía al usuario sensaciones táctiles a través de dispositivos hápticos, para lo cual se modeló el instrumental quirúrgico necesario. Se propone una forma de simular piel humana con diferentes características como grosor, flexibilidad, textura, etc. Se plantea un método de generación de respuesta háptica (haptic rendering) para superficies deformables aplicado a dicha piel. Se desarrolla un hilo que posee características que le permiten fijarse a una superficie deformable, colisionar con objetos sólidos y generar nudos simples. Como producto final de esta investigación, se muestra la integración e interacción de los diversos elementos citados anteriormente para generar el ambiente virtual de entrenamiento médico para realización de sutura: SutureHap. Las pruebas realizadas por los usuarios en el ambiente muestran que el comportamiento del mismo es cercano a un ambiente real y que puede ser usado para el entrenamiento de futuros médicos.
    • Crecimiento concomitante de capas durante la nitruración por el plasma de hierro puro : modelado matemático, simulación y validación experimental

      Antonio Jiménez Ceniceros; ANTONIO JIMÉNEZ CENICEROS (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2016)
    • Análisis y diseño de una topología de inversor multinivel basada en primas poligonales para aplicación en energías alternas

      Aldo Elihu Flores González; ALDO ELIHU FLORES GONZÁLEZ (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2016)
    • WebMC : a model checker for the Web

      Victor Ferman; VICTOR FERMAN (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2016)
    • Suboptimal structures of channel encoding for fade mitigation in satellite communications

      David, Villena Rivera; DAVID, VILLENA RIVERA (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2015)
    • Análisis metabolómico diferencial en fruto de chile habanero (Capsicum chinense Jacq.) durante maduración y en respuesta a condiciones edáficas subóptimas

      Urrea López, Rafael (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2014-05-01)
      El chile habanero (Capsicum chinense, Jacq.) es un fruto de alto valor, apreciado por sus propiedades organolépticas de sabor y elevada pungencia. Sin embargo, su producción se ve limitada por la escasez de variedades altamente productivas con buen desempeño ante estreses bióticos y abióticos. El objetivo de este estudio fue caracterizar los efectos de la exposición prolongada a condiciones edafológicas subóptimas en el estatus metabolómico del fruto de chile habanero durante maduración, utilizando e implementando técnicas de metabolómica dirigida y no-dirigida; así como también caracterizar la respuesta fisiológica general de la planta y su rendimiento. Para ello se sometieron plantas de chile habanero a tratamientos de bajo P, bajo N y dos niveles de salinidad (4 y 7 dS·m-1), en cultivo hidropónico con fertirriego basado en solución nutritiva Hoagland, aplicado desde el inicio de floración. A través de técnicas dirigidas se evaluó la respuesta de fotosíntesis de la planta, de partición de biomasa, y de metabolitos relacionados con calidad en frutos maduros (capsaicinoides, ascorbato, carotenoides, fenólicos y azúcares). El perfil de los cambios en metaboloma durante maduración y por efecto de los tratamientos se evaluó a través de HPLC-ESI-TOF en pericarpio de frutos en tres estados de maduración; el procesamiento de datos se realizó con MZmine y los datos se analizaron con modelo lineal de efectos mixtos (MLEM p ≤0.001) programado en R; la identificación tentativa se asignó por comparación de patrones de fragmentación obtenidos por MS/MS.