Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Domain-adapted pretraining and topic modeling for identifying skills categories in job postings(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-12-05) Madera Espíndola, Diana Patricia; Ceballos Cancino, Héctor Gibrán; Vázquez Lepe, Elisa Virginia; mtyahinojosa, emipsanchez; González Gómez, Luis José; Fahim Siddiqui, Muhammad Hammad; Cantú Ortiz, Francisco Javier; Escuela de Ingeniería y Ciencias; Campus Estado de México; Butt, SaburThe need to identify and cluster related skills in job postings has become increasingly essential as the labor market becomes more complex, driven by the rapid growth in job market data and continuous shifts in economic conditions, technology, and skill requirements. This task is especially challenging for postings in low-resources languages such as Spanish, as there is a lack of models specifically trained to handle these language variations. Previous work in this regard involves taxonomies created by experts such as ESCO, intended to be used as reference points via measured skills. However, some issues associated with these systems stem from their reliance on region-specific taxonomies as well as their rigidity to adapt to the changing environment of the market. Thus, we proposed a method to improve skill identification performance within the Mexican automotive industry by grouping equivalent skills present in Spanish job postings through the integration of text normalization, a Domain-Adaptive Pre-training (DAPT) Spanish BERT model, the use of BERTopic for pseudo-labels extraction, the improvement of vocabulary representation via VGCN embeddings, and similarity metrics such as keyword overlap and cosine similarity for final refined clustering. The scope of this research is to evaluate our approach by using an Adjusted Rand Index (ARI) score in skill classification on a dataset exhibiting a long-tail distribution across both the head and tail data, comparing the results to those of an initial Non-DAPT model, since, to the best of our knowledge, no direct approach exists that is comparable to either our ensemble model or the distribution of our dataset.
- Upcycling alkaline maize cooking wastewater (nejayote) for sustainable lettuce (Lactuca sativa) cultivation: Biotechnological innovations for waste-to-food systems(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-12-03) Cervantes López, Alexa; Escalante Aburto, Anayansi; Vázquez Lepe, Elisa Virginia; mtyahinojosa, emipsanchez; Gutiérrez Uribe, Janet Alejandra; Domínguez Hernández, Martha Elena; School of Engineering and Sciences; Campus Monterrey; Franco Morgado, MarianaThe maize processing industry produces large volumes of alkaline maize cooking wastewater (nejayote), presenting both an environmental challenge and a valorization opportunity. This study examines microbial dynamics, metabolomic shifts, and agronomic potential of nejayote fermented for six days in a high-rate algal pond (HRAP) inoculated with an alkaliphilic microorganism consortium (AMC). Untreated fermentation led to a 65.3% increase in total suspended solids (TSS), while AMC inoculation prevented chemical oxygen demand (COD) increase. Metagenomic analysis revealed a shift from Enterobacteriaceae (45-47%) and Xanthomonadaceae (29-34%) to Cyclobacteriaceae (39%) and Dermocarpellaceae (>50%) in AMC-treated systems. By day six of fermentation process, pathogenic bacteria dropped below 2%, supporting ecosystem functionality and bioremediation. Cyclobacteriaceae, a non-pathogenic family, is relevant for wastewater treatment and bioactive compound production. Untargeted metabolomics identified pentose and glucuronate interconversions, starch/sucrose metabolism, and key monomers (xylose, arabinose), along with amino acids, phenolics, terpenoids, carotenoids, and pesticide-associated signals indicative of partial degradation or transformation. Furthermore, to evaluate nejayote’s upcycle potential in fresh food production, fermented AMC-inoculated nejayote treatments (M1: 0-1 days, M3: 2-3 days, M5: 4-5 days) were used to replace one-third of irrigation water for lettuce (Lactuca sativa) cultivation over eight weeks. Compared to water controls, M3 increased lettuce fresh weight by 109.9% and total phenolic content (TPC) by 313.2%, while M5 enhanced TPC by 173.8%. In contrast, untreated nejayote reduced fresh weight by 33.7%. AMC fermentation promoted the potential accumulation of phenolic and polyphenolic compounds, along with stress-associated fatty acids that act as plant elicitors. The carotenoid pathway was biologically and statistically significant in treatment-irrigated lettuces. Irrigation frequency, applied once or twice per week, influenced the macroscopical features of lettuce; however, twice-weekly irrigation did not result in greater fresh leaf weight or length. Additionally, soil water holding capacity of the treatments was comparable to water and M3 did not affect pH over the 8-week period. Demonstrating the potential of this system for agro-industrial wastewater upcycling, contributing to sustainable agriculture, freshwater conservation, and circular bioeconomy strategies.
- Development of MgF2/PDO coating for a resorbable WE43 Mg alloy esophageal stent(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06-13) Arreguín Ortega, Pablo de Jesús; Vázquez Lepe, Elisa Virginia; emimmayorquin; García López, Erika; Rodríguez González, Ciro Ángel; School of Engineering and Sciences; Campus Monterrey; Cortés Capetillo, Azael JesúsDesign Thinking (DT) is a human-centered methodology of five phases that considers users’ needs and problems as the core insights to design unique products and services. Hence, the development of medical devices could be guided by DT and other innovation approaches like Product Design and Development and Concurrent Engineering. The intersection of these methodologies is explored to develop a resorbable esophageal stent for bariatric complications. Besides, Mg alloys have being explored for biomedical applications due to their biocompatibility and resorbability. However, degradation rates limit their application on medical devices. Conversion coating is generated over WE43 Mg alloy substrates defining concentration of Hydrofluoric Acid (HF) of 10, 20, and 40 v/v% and immersion time for 3, 6, 12, and 24 hours. Surface morphology, chemical composition and elements distribution were characterized through SEM and EDS techniques. Layer thickness and water contact angles were also measured. Moreover, polymeric films were ultrasonically atomized using PLA: DCM solutions of 0.5, 1, 2, 4, 6 wt% and PDO: HFIP solutions of 0.5, and 1 wt%, based on rheological characterizations of shear and specific viscosity. Surface morphology was characterized, and film thickness was measured, setting atomization time (1, 5, 10, and 15 minutes) and polymer concentration as main factors.
- Development of a polymeric aortic valve implant for manufacture in Ultrasonic Injection Molding(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2023-12-05) Rubio Maldonado, Mariana; Vázquez Lepe, Elisa Virginia; emimmayorquin; García López, Erika; Rodríguez González, Ciro Ángel; Departamento de Ingeniería Mecánica y Materiales Avanzados; Campus MonterreyThis thesis, part of the Master of Science in Manufacturing Systems program, presents an innovative proposal to address the challenges inherent in biological heart valve implants, specifically those crafted from animal pericardium. Focusing on the development of a polymeric aortic valve implant prototype, the study employs Ultrasonic Injection Molding (UIM) technology known for its capabilities in minimizing material waste and enhancing manufacturing efficiency. The research delves into the nuances of UIM manufacturing, investigating the processing window’s best parameters and conducting a following optimization to improve the mechanical properties of the resulting implant. The mechanical characterization of Thermoplastic Polyurethane (TPU), the chosen material, adds depth to the understanding of its behavior, ensuring suitability for medical applications. Complementing the manufacturing advancements, the study includes the design and prototyping of the aortic valve implant. Subsequent simulation through Computer-Aided Engineering (CAE) is employed to analyze the fluid dynamics facilitated by the valve design. This approach aims to provide comprehensive insights into the performance and efficacy of the polymeric aortic valve implant. Motivated by the limitations of traditional biological heart valve implants, including the necessity for reimplantation and the intricate, artisanal manufacturing processes leading to the wastage of animal pericardium, this research introduces a forward-thinking solution. Leveraging UIM technology, optimizing processing parameters, and integrating CAE simulation, the study seeks to innovate aortic valve implant manufacturing, offering a more efficient and resilient alternative to current practices.
- Finite element simulation of the mechanical performance of a WE43 magnesium‐alloy biliary stent(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2023) Serrato Lara, Diana Laura; Vázquez Lepe, Elisa Virginia; emipsanchez; Rodríguez González, Ciro Angel; García López, Erika; Escuela de Ciencias e Ingeniería; Campus Monterrey; Pérez Santiago, RogelioThis thesis presents a research endeavor focused on designing a biliary stent to address complications arising from laparoscopic cholecystectomy, with a specific emphasis on bile duct injuries. This work emphasizes the development of a biodegradable magnesium-based alloy stent (WE43). Using the finite element method (FEM), this study aims to simulate the mechanical behavior of the WE43 magnesium alloy biliary stent through non-clinical tests, including a three-point bending test and balloon expansion. Critical to this simulation is the validation process, a material characterization of the WE43 magnesium alloy and a meticulous analysis of the stent's mechanical properties under varied boundary conditions is performed. The research proposes a stage gate process for the development of the biodegradable biliary stent and introduces a methodology for the characterization of the WE43 magnesium alloy, improving the accuracy of experimental predictions. The outcomes demonstrate the efficacy of the Finite Element Method in predicting stent deformation under diverse physiological conditions, particularly in three-point bending and balloon expansion tests.
- Influence of process parameters on surface topography of nitinol manufactured by fiber laser cutting for medical applications(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-09) Cadena Calvillo, Mariana; VAZQUEZ LEPE, ELISA VIRGINIA; 268852; Vázquez Lepe, Elisa Virginia; puelquio/mscuervo; Rodríguez González, Ciro Ángel; López Botello, Omar Eduardo; School of Engineering and Sciences; Campus Monterrey; García López, ErikaThe need and tendency to develop medical devices on the micron scale has created an opportunity to micro cutting processes that have the capability of manufacturing quality medical devices. Thereby, the necessity of materials that have unique features to improve the deliverability and the performance of these devices have made nitinol one of the most selected materials for this industry. Nevertheless, the study of the micro processing of nitinol tube for the application on medical devices, through fiber laser cutting and its response to surface quality has not been thoroughly researched. Hence, in this research the response of fiber laser cutting parameters, such as spot overlapping and pulse energy, on Ni-Ti alloy (nitinol) was statistically analyzed through surface quality through average surface roughness, and heat-affected zone. Results showed that spot overlap had most impact on surface quality, since surface roughness decreased increasing spot overlap, but further increase resulted on increased surface. Minimum surface roughness of 1.482 µm, with 83.72% of spot overlap and 72.16 of pulse energy. Presence of HAZ, and dross found on highest values of spot overlap and pulse energy. In conclusion, fiber laser cutting has the capability to produce high surface quality nitinol self-expanding stents.
- Design and fabrication of transdermal microneedle inserts by Stereolithography for Ultrasonic Injection Molding(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-08) Villa Carrillo, Karla Marcela; Vázquez Lepe, Elisa Virginia; tolmquevedo; García López, Erika; Rodríguez González, Ciro Angel; School of Engineering and Sciences; Campus Monterrey; Martínez López, José IsraelIn this work design of a transdermal microneedle patches with hexagonal and squared cross-sections are explored using stereolithography for manufacturing ultrasonic injection molding inserts. A multi-cavity mold was designed using Finite Element Method based software, where polypropylene injection molding simulations were performed for design optimization. Manufacture of the proposed device was assessed using a stereolithography based additive manufacturing equipment suitable for high temperature applications. Dimensional accuracy was evaluated using three-dimensional metrology. Deviational height errors of 18.05% and 39.21% were found for the hexagonal and square microneedle insert cavities. A successful proof-of-concept ultrasonic injection molding is a step forward for manufacturing of microneedles for the point-of-care.
- Manufacturability of PLA parts reinforced with TiO2 nanoparticles by ultrasonic molding.(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-06-16) Macías Naranjo, Mariana; VAZQUEZ LEPE, ELISA VIRGINIA; 268852; Vázquez Lepe, Elisa Virginia; mla, emipsanchez; Ortega Lara, Wendy de Lourdes; Rodríguez González, Ciro Angel; School of Engineering and Sciences; Campus Monterrey; Ferrer Real, InésThe objective of the thesis is to define and to validate a methodology for the stabilization of process parameters in ultrasonic molding and to analyze the manufacturability of PLA parts reinforced with TiO2 nanoparticles in the ultrasonic molding process. Ultrasonic molding is a new technology used for micro-part molding, reducing the necessary energy, process times, and material waste. Validating a methodology for this process, PLA was processed with TiO2 nanoparticles to observe the response of the process in this combination of materials. In addition, to observe the influence of the concentration of nanoparticles by performing the characterization to find an application in the medical sector in the future.
- Evaluation of the dimensional capabilities for the technologies of selective laser melting and digital light processing, to fabricate microcavities: microneedle insert as case of study.(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-06-16) Meneses Ricaurte, Cindy Paola; Vázquez Lepe, Elisa Virginia; emipsanchez/tolmquevedo; Sandoval Robles, Jesús Alejandro; Rodríguez González, Ciro Ángel; School of Engineering and Sciences; Campus Monterrey; García López, ErikaAdditive manufacturing technologies are nowadays a feasible resource in micro parts fabrication, which have a wide range of applications from medical industry to injection molding. These technologies allow fabrication of complex parts with a variety of geometries and sizes that ultimately gives a competitive advantage by letting the manufacturing of insert molds. This research study the dimensional capabilities of selective laser melting and digital light processing to produce microneedle cavities from 500 μm to 2500 μm. An insert for microneedle was manufactured variating its bases geometries and successfully fabricated through selective laser melting at 0°, 45° and 90° orientations. Similarly, for the digital light processing technology, inserts for microneedle geometries were manufactured at 0° and 45° build surface orientation. It was found for the hexagonal base geometry, the best for both technologies with the lower dimensional errors, due to a common factor between processes called stair steeping. By using a reduction in border and contour power, height dimensional accuracy of the microneedle insert was improved. There was a minimum error of 3% for 600 μm of nominal height corresponding to the fabricated insert by selective laser melting at 0°orientation of construction with the optimal design.
- Micro machinability of net shapes of Selective Laser Melting of Ti-6Al-4V for minimum material removal using ball end mill(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15) Celis Renata, Pavel; Vázquez Lepe, Elisa Virginia; García López, Erika; Rodríguez González, Ciro Ángel; Sandoval Robles, Jesús A.Miniaturization of medical devices is playing an important role in the manufacture industry. New drug delivery systems are being studied and developed, therefore materials to produce these devices must be investigated extensively. The objective of this work is to experimentally investigate and compare the machinability of Ti-6Al-4V titanium alloy produced via Selective laser melting (SLM) against the conventional machining method. 18 patches of 09 needles each were fabricated and machined with different cutting feeds (120,150 and 180mm/min) with aid of a minimum quantity lubrication (MQL) system. Machinability was examined in terms of cutting forces, tool wear, surface roughness and geometrical dimensions. Each cutting feed was tested by fabricating 3 patches from solid blocks of titanium with square tools of .8mm. Finish pass was performed with a .2mm micro ball end mill with a constant spiral toolpath. Comparison was performed by fabricating four patches with SLM with an excess material of 150μm and machined with the same previous parameters. 3D images obtained by optical microscope reveal that the main force applied in the finishing of needles is the Z axis and cutting forces were higher when machining SLM patches. Tool calibration is the main factor to obtain high precision in geometrical dimensions due to the variation in length because of thermal expansion. Surface roughness for all tests were below 1μm with best results when cutting feed is set at 120mm/min, reduction in edge radius for ball end mills affected negatively the surface roughness. An economic comparison was performed and showed that the SLM combined with SM process has clear advantage over subtractive manufacture alone.