61 research outputs found

    Neural Network Inverse Modeling for Optimization

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    In this chapter, artificial neural networks (ANNs) inverse model is applied for estimating the thermal performance () in parabolic trough concentrator (PTC). A recurrent neural network architecture is trained using the Kalman Filter learning from experimental database obtained from PTCs operations. Rim angle (φr), inlet (Tin), outlet (Tout) fluid temperatures, ambient temperature (Ta), water flow (Fw), direct solar radiation (Gb) and the wind velocity (Vw) were used as main input variables within the neural network model in order to estimate the thermal performance with an excellent agreement (R2=0.999) between the experimental and simulated values. The optimal operation conditions of parabolic trough concentrator are established using artificial neural network inverse modeling. The results, using experimental data, showed that the recurrent neural network (RNN) is an excellent tool for modeling and optimization of PTCs

    Proyecto de exportación de los insumos, equipos y materiales relacionados con la masa de maíz hacia la Unión Europea

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    El proyecto de internacionalización de Lusio se basó en un alcance de la investigación en la Unión Europea con los objetivos específicos que tenían un enfoque en los siguientes siete apartados: empresa, producto, mercado, comercialización, logística, legal y finanzas. Dentro de la administración del proyecto, se buscó una planeación, organización y dirección de los recursos disponibles para el cumplimiento de las metas y objetivos del plan desarrollado. En su proceso, se contó con distintos referentes teóricos que ayudaron a tomar decisiones fundamentadas para la comprensión de las necesidades de la empresa y su intervención. Parte de su metodología se basó en una división de los entregables del trabajo dentro del equipo para su elaboración tanto de manera presencial como trabajo en línea haciendo uso de plataformas para la constante comunicación. Así mismo, en los resultados encontrados, se resaltan las características principales de la línea de productos a distribuir en el mercado internacional, investigación de mercado enfocada en Alemania y España, estrategias de distribución emparejadas a las de la competencia para crear ventajas competitivas, un plan logístico, la presentación de documentos legales como contratos de compraventa y de transporte y, al finalizar, se presentaron conclusiones y recomendaciones que se fueron encontrando con el seguimiento del proyecto para la creación de estrategias que posicionen a Lusio en el mercado europeo, aprovechando la oportunidad que existe en estos mercados.ITESO, A.C

    Morphometric characteristics of lumbar vertebral pedicles in Mexican population. Implications for transpedicular lumbar fusion surgery

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    Introduction. Spinal fusion surgery using transpedicular fixation is the most common technique for surgical treatment of spinal pathologies of any etiology. The morphometric characteristics of the vertebral pedicle determine the size and shape of pedicle implants. The objective of this study is to determine the morphometric characteristics of the lumbar vertebral pedicle in Mexican population by direct measurement of bone parts. Materials and Methods. We analyzed 65 L1–L5 cadaver lumbar spines from a collection of bone specimens from the Department of Human Anatomy. Pedicle width, height, and length were determined bilaterally in each sample studied. We obtained measures of central tendency, and parametric correlation tests were performed with a 95% confidence interval to determine if significant differences exist between the lumbar vertebral levels. Results. Pedicle width increased from L1 to L5. We obtained a minimum mean value of 7.40 ± 1.84 mm at L1 and a maximum mean value of 14.74 ± 3.77 mm at L5. Pedicle height decreased from L1 to L4 with a subsequent increase at L5. We obtained a maximum mean value of 18.32 ± 4.15 mm at L5 and minimum mean value of 14.09 mm ± 2.75 at L4. Significant differences were observed (P < 0.05) when groups were compared. Conclusions. This study accurately describes the morphometric characteristics of the lumbar vertebral pedicle. These data will be useful for correct selection and positioning of transpedicular screws

    Determination of essential biomarkers in lung cancer : a real-world data study in Spain with demographic, clinical, epidemiological and pathological characteristics

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    Background The survival of patients with lung cancer has substantially increased in the last decade by about 15%. This increase is, basically, due to targeted therapies available for advanced stages and the emergence of immunotherapy itself. This work aims to study the situation of biomarker testing in Spain. Patients and methods The Thoracic Tumours Registry (TTR) is an observational, prospective, registry-based study that included patients diagnosed with lung cancer and other thoracic tumours, from September 2016 to 2020. This TTR study was sponsored by the Spanish Lung Cancer Group (GECP) Foundation, an independent, scientific, multidisciplinary oncology society that coordinates more than 550 experts and 182 hospitals across the Spanish territory. Results Nine thousand two hundred thirty-nine patients diagnosed with stage IV non-small cell lung cancer (NSCLC) between 2106 and 2020 were analysed. 7,467 (80.8%) were non-squamous and 1,772 (19.2%) were squamous. Tumour marker testing was performed in 85.0% of patients with non-squamous tumours vs 56.3% in those with squamous tumours (p-value < 0.001). The global testing of EGFR, ALK, and ROS1 was 78.9, 64.7, 35.6% respectively, in non-squamous histology. PDL1 was determined globally in the same period (46.9%), although if we focus on the last 3 years it exceeds 85%. There has been a significant increase in the last few years of all determinations and there are even close to 10% of molecular determinations that do not yet have targeted drug approval but will have it in the near future. 4,115 cases had a positive result (44.5%) for either EGFR, ALK, KRAS, BRAF, ROS1, or high PDL1. Conclusions Despite the lack of a national project and standard protocol in Spain that regulates the determination of biomarkers, the situation is similar to other European countries. Given the growing number of different determinations and their high positivity, national strategies are urgently needed to implement next-generation sequencing (NGS) in an integrated and cost-effective way in lung cancer

    Respiratory viruses detected in Mexican children younger than 5 years old with community-acquired pneumonia: a national multicenter study

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    Background: Acute respiratory infections are the leading cause of mortality in children worldwide, especially in developing countries. Pneumonia accounts for 16% of all deaths of children under 5 years of age and was the cause of death of 935 000 children in 2015. Despite its frequency and severity, information regarding its etiology is limited. The aim of this study was to identify respiratory viruses associated with community-acquired pneumonia (CAP) in children younger than 5 years old. Methods: One thousand four hundred and four children younger than 5 years of age with a clinical and/or radiological diagnosis of CAP in 11 hospitals in Mexico were included. Nasal washes were collected, placed in viral medium, and frozen at �70 C until processing. The first 832 samples were processed using the multiplex Bio-Plex/Luminex system and the remaining 572 samples using the Anyplex multiplex RT-PCR. Clinical data regarding diagnosis, clinical signs and symptoms, radiographic pattern, and risk factors were obtained and recorded. Results: Of the samples tested, 81.6% were positive for viruses. Respiratory syncytial virus (types A and B) was found in 23.7%, human enterovirus/rhinovirus in 16.6%, metapneumovirus in 5.7%, parainfluenza virus (types 1–4) in 5.5%, influenza virus (types A and B) in 3.6%, adenovirus in 2.2%, coronavirus (NL63, OC43, 229E, and HKU1) in 2.2%, and bocavirus in 0.4%. Co-infection with two or more viruses was present in 22.1%; 18.4% of the samples were negative. Using biomass for cooking, daycare attendance, absence of breastfeeding, and co-infections were found to be statistically significant risk factors for the presence of severe pneumonia. Conclusions: Respiratory syncytial virus (types A and B), human enterovirus/rhinovirus, and metapneumovirus were the respiratory viruses identified most frequently in children younger than 5 years old with CAP. Co-infection was present in an important proportion of the children

    Relationship between morphological features and kinetic patterns of enhancement of the dynamic breast magnetic resonance imaging and clinico-pathological and biological factors in invasive breast cancer

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    <p>Abstract</p> <p>Background</p> <p>To investigate the relationship between the magnetic resonance imaging (MRI) features of breast cancer and its clinicopathological and biological factors.</p> <p>Methods</p> <p>Dynamic MRI parameters of 68 invasive breast carcinomas were investigated. We also analyzed microvessel density (MVD), estrogen and progesterone receptor status, and expression of p53, HER2, ki67, VEGFR-1 and 2.</p> <p>Results</p> <p>Homogeneous enhancement was significantly associated with smaller tumor size (T1: < 2 cm) (p = 0.015). Tumors with irregular or spiculated margins had a significantly higher MVD than tumors with smooth margins (p = 0.038). Tumors showing a maximum enhancement peak at two minutes, or longer, after injecting the contrast, had a significantly higher MVD count than those which reached this point sooner (p = 0.012). The percentage of tumors with vascular invasion or high mitotic index was significantly higher among those showing a low percentage (≤ 150%) of maximum enhancement before two minutes than among those ones showing a high percentage (>150%) of enhancement rate (p = 0.016 and p = 0.03, respectively). However, there was a significant and positive association between the mitotic index and the peak of maximum intensity (p = 0.036). Peritumor inflammation was significantly associated with washout curve type III (p = 0.042).</p> <p>Conclusions</p> <p>Variations in the early phase of dynamic MRI seem to be associated with parameters indicatives of tumor aggressiveness in breast cancer.</p

    Clinical practice guideline for surgical antimicrobial prophylaxis

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    La infección del sitio quirúrgico (ISQ) es una de las principales causas de infecciones asociadas a la atención en salud (IAAS), con un impacto significativo en la mortalidad y morbilidad del paciente quirúrgico, así como en los costos asociados a la atención en salud. El adecuado uso de la profilaxis quirúrgica antimicrobiana es un aspecto fundamental en la reducción del riesgo de ISQ, dado que su utilización inapropiada o indiscriminada puede representar un riesgo para los pacientes y contribuir al desarrollo de resistencia a los antimicrobianos, por lo que resulta de importancia generar directrices que permitan orientar el uso adecuado de antimicrobianos en la profilaxis del paciente quirúrgico, con el objetivo de obtener mejores desenlaces clínicos y propender por un uso racional de antibióticos. La presente guía contiene recomendaciones para profilaxis antibiótica de pacientes sometidos a procedimiento quirúrgico, basadas en la evidencia, realizadas mediante el proceso de adaptación de guías de práctica clínica para el contexto colombiano.Q4Pacientes sometidos a Profilaxis quirúrgica antimicrobianaSurgical site infection (SSI) is one of the main causes of healthcare associated infections (HAI), with a significant impact on the mortality and morbidity of the surgi-cal patient, as well as on the costs associated with health care. The adequate use of surgical antimicrobial prophylaxis being a fundamental aspect in reducing the risk of SSI, taking into account that the inappropriate or indiscriminate use of antibiotics in surgical prophylaxis may represent a risk for patients and contribute to the development of antimicrobial resistance, so it is important to generate guidelines that guide the appropriate antimicrobial prophylaxis in the surgical patient, with the aim of obtaining better clinical outcomes and promoting a rational use of antibiotics. This guide contains recommendations for antibiotic prophylaxis in patients undergoing a surgical procedure, based on evidence, carried out through the process of adapting clinical practice guidelines for the Colombian context.https://orcid.org/0000-0002-5392-7083https://orcid.org/0000-0003-2568-4667Revista Nacional - IndexadaCN

    Impact of treatment and clinical characteristics on the survival of children with medulloblastoma in Mexico

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    IntroductionData on medulloblastoma outcomes and experiences in low- and middle-income countries, especially in Latin America, is limited. This study examines challenges in Mexico’s healthcare system, focusing on assessing outcomes for children with medulloblastoma in a tertiary care setting.MethodsA retrospective analysis was conducted, involving 284 patients treated at 21 pediatric oncology centers in Mexico.ResultsHigh-risk patients exhibited markedly lower event-free survival than standard-risk patients (43.5% vs. 78.3%, p&lt;0.001). Influential factors on survival included anaplastic subtype (HR 2.4, p=0.003), metastatic disease (HR 1.9, p=0.001); residual tumor &gt;1.5cm², and lower radiotherapy doses significantly impacted event-free survival (EFS) and overall survival (OS). Platinum-based chemotherapy showed better results compared to the ICE protocol in terms of OS and EFS, which was associated with higher toxicity. Patients under 3 years old displayed notably lower OS and EFS compared to older children (36.1% vs. 55.9%, p=0.01)

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
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