Defining multivariate raw material specifications via SMB-PLS

[EN] The Sequential Multi-Block Partial Least Squares (SMB-PLS) model inversion is applied for defining analytically the multivariate raw material region providing assurance of quality with a certain confidence level for the critical to quality attributes (CQA). The SMB-PLS algorithm does identify the variation in process conditions uncorre-lated with raw material properties and known disturbances, which is crucial to implement an effective process control system attenuating most raw material variations. This allows expanding the specification region and, hence, one may potentially be able to accept lower cost raw materials that will yield products with perfectly satisfactory quality properties. The methodology can be used with historical/happenstance data, typical in In-dustry 4.0. This is illustrated using simulated data from an industrial case study.This work was partially supported by the Spanish Ministry of Science and Innovation (PID2020-119262RB-I00) , the Generalitat Valenciana (AICO/2021/111) and the European Social Fund (ACIF/2018/165) .Borràs-Ferrís, J.; Duchesne, C.; Ferrer, A. (2023). Defining multivariate raw material specifications via SMB-PLS. Chemometrics and Intelligent Laboratory Systems. 240. https://doi.org/10.1016/j.chemolab.2023.10491224

Link-Level Functional Connectivity Neuroalterations in Autism Spectrum Disorder: A Developmental Resting-State fMRI Study

[EN] Autism spectrum disorder (ASD) is a neurological and developmental disorder whose late diagnosis is based on subjective tests. In seeking for earlier diagnosis, we aimed to find objective biomarkers via analysis of resting-state functional MRI (rs-fMRI) images obtained from the Autism Brain Image Data Exchange (ABIDE) database. Thus, we estimated brain functional connectivity (FC) between pairs of regions as the statistical dependence between their neural-related blood-oxygen-level-dependent (BOLD) signals. We compared FC of individuals with ASD and healthy controls, matched by age and intelligence quotient (IQ), and split into three age groups (50 children, 98 adolescents, and 32 adults), from a developmental perspective. After estimating the correlation, we observed hypoconnectivities in children and adolescents with ASD between regions belonging to the default mode network (DMN). Concretely, in children, FC decreased between the left middle temporal gyrus and right frontal pole (p = 0.0080), and between the left orbitofrontal cortex and right superior frontal gyrus (p = 0.0144). In adolescents, this decrease was observed between bilateral postcentral gyri (p = 0.0012), and between the right precuneus and right middle temporal gyrus (p = 0.0236). These results help to gain a better understanding of the involved regions on autism and its connection with the affected superior cognitive brain functions.This research was partially funded by the Ministerio de Economia y Competitividad (MINECO), through the project BFU2015-64380-C2-2-R. U.P.-R. is funded by the Spanish Ministerio de Educacion, Cultura y Deporte (MECD) under grant FPU13/03537. We are thankful to the initiative ABIDE to provide the huge public release and open sharing autism database what has made possible to carry out this study in better conditions and improve the results obtained significantly.Borràs-Ferrís, L.; Pérez-Ramírez, MÚ.; Moratal, D. (2019). Link-Level Functional Connectivity Neuroalterations in Autism Spectrum Disorder: A Developmental Resting-State fMRI Study. Diagnostics. 9(1):1-10. https://doi.org/10.3390/diagnostics9010032S11091Hull, J. V., Dokovna, L. B., Jacokes, Z. J., Torgerson, C. M., Irimia, A., & Van Horn, J. D. (2017). Resting-State Functional Connectivity in Autism Spectrum Disorders: A Review. Frontiers in Psychiatry, 7. doi:10.3389/fpsyt.2016.00205Mertz, L. (2017). Sharing Data to Solve the Autism Riddle: An Interview with Adriana Di Martino and Michael Milham of ABIDE. IEEE Pulse, 8(6), 6-9. doi:10.1109/mpul.2017.2750819Cociu, B. A., Das, S., Billeci, L., Jamal, W., Maharatna, K., Calderoni, S., … Muratori, F. (2018). Multimodal Functional and Structural Brain Connectivity Analysis in Autism: A Preliminary Integrated Approach With EEG, fMRI, and DTI. IEEE Transactions on Cognitive and Developmental Systems, 10(2), 213-226. doi:10.1109/tcds.2017.2680408Dekhil, O., Hajjdiab, H., Shalaby, A., Ali, M. T., Ayinde, B., Switala, A., … El-Baz, A. (2018). Using resting state functional MRI to build a personalized autism diagnosis system. PLOS ONE, 13(10), e0206351. doi:10.1371/journal.pone.0206351Rogers, B. P., Morgan, V. L., Newton, A. T., & Gore, J. C. (2007). Assessing functional connectivity in the human brain by fMRI. Magnetic Resonance Imaging, 25(10), 1347-1357. doi:10.1016/j.mri.2007.03.007Cheng, W., Rolls, E. T., Gu, H., Zhang, J., & Feng, J. (2015). Autism: reduced connectivity between cortical areas involved in face expression, theory of mind, and the sense of self. Brain, 138(5), 1382-1393. doi:10.1093/brain/awv051Lynch, C. J., Uddin, L. Q., Supekar, K., Khouzam, A., Phillips, J., & Menon, V. (2013). Default Mode Network in Childhood Autism: Posteromedial Cortex Heterogeneity and Relationship with Social Deficits. Biological Psychiatry, 74(3), 212-219. doi:10.1016/j.biopsych.2012.12.013Uddin, L. Q., Supekar, K., Lynch, C. J., Khouzam, A., Phillips, J., Feinstein, C., … Menon, V. (2013). Salience Network–Based Classification and Prediction of Symptom Severity in Children With Autism. JAMA Psychiatry, 70(8), 869. doi:10.1001/jamapsychiatry.2013.104Di Martino, A., Kelly, C., Grzadzinski, R., Zuo, X.-N., Mennes, M., Mairena, M. A., … Milham, M. P. (2011). Aberrant Striatal Functional Connectivity in Children with Autism. Biological Psychiatry, 69(9), 847-856. doi:10.1016/j.biopsych.2010.10.029Washington, S. D., Gordon, E. M., Brar, J., Warburton, S., Sawyer, A. T., Wolfe, A., … VanMeter, J. W. (2013). Dysmaturation of the default mode network in autism. Human Brain Mapping, 35(4), 1284-1296. doi:10.1002/hbm.22252Assaf, M., Jagannathan, K., Calhoun, V. D., Miller, L., Stevens, M. C., Sahl, R., … Pearlson, G. D. (2010). Abnormal functional connectivity of default mode sub-networks in autism spectrum disorder patients. NeuroImage, 53(1), 247-256. doi:10.1016/j.neuroimage.2010.05.067Weng, S.-J., Wiggins, J. L., Peltier, S. J., Carrasco, M., Risi, S., Lord, C., & Monk, C. S. (2010). Alterations of resting state functional connectivity in the default network in adolescents with autism spectrum disorders. Brain Research, 1313, 202-214. doi:10.1016/j.brainres.2009.11.057Kennedy, D. P., & Courchesne, E. (2008). The intrinsic functional organization of the brain is altered in autism. NeuroImage, 39(4), 1877-1885. doi:10.1016/j.neuroimage.2007.10.052Mueller, S., Keeser, D., Samson, A. C., Kirsch, V., Blautzik, J., Grothe, M., … Meindl, T. (2013). Convergent Findings of Altered Functional and Structural Brain Connectivity in Individuals with High Functioning Autism: A Multimodal MRI Study. PLoS ONE, 8(6), e67329. doi:10.1371/journal.pone.0067329Von dem Hagen, E. A. H., Stoyanova, R. S., Baron-Cohen, S., & Calder, A. J. (2012). Reduced functional connectivity within and between ‘social’ resting state networks in autism spectrum conditions. Social Cognitive and Affective Neuroscience, 8(6), 694-701. doi:10.1093/scan/nss053Uddin, L. Q., Supekar, K., & Menon, V. (2013). Reconceptualizing functional brain connectivity in autism from a developmental perspective. Frontiers in Human Neuroscience, 7. doi:10.3389/fnhum.2013.00458Kana, R. K., Uddin, L. Q., Kenet, T., Chugani, D., & Müller, R.-A. (2014). Brain connectivity in autism. Frontiers in Human Neuroscience, 8. doi:10.3389/fnhum.2014.00349Beckmann, C. F., & Smith, S. M. (2004). Probabilistic Independent Component Analysis for Functional Magnetic Resonance Imaging. IEEE Transactions on Medical Imaging, 23(2), 137-152. doi:10.1109/tmi.2003.822821Cole. (2010). Advances and pitfalls in the analysis and interpretation of resting-state FMRI data. Frontiers in Systems Neuroscience. doi:10.3389/fnsys.2010.00008Etzel, J. A., Gazzola, V., & Keysers, C. (2009). An introduction to anatomical ROI-based fMRI classification analysis. Brain Research, 1282, 114-125. doi:10.1016/j.brainres.2009.05.090Di Martino, A., Yan, C.-G., Li, Q., Denio, E., Castellanos, F. X., Alaerts, K., … Milham, M. P. (2013). The autism brain imaging data exchange: towards a large-scale evaluation of the intrinsic brain architecture in autism. Molecular Psychiatry, 19(6), 659-667. doi:10.1038/mp.2013.78Cameron, C., Yassine, B., Carlton, C., Francois, C., Alan, E., András, J., … Pierre, B. (2013). The Neuro Bureau Preprocessing Initiative: open sharing of preprocessed neuroimaging data and derivatives. Frontiers in Neuroinformatics, 7. doi:10.3389/conf.fninf.2013.09.00041Xu, T., Yang, Z., Jiang, L., Xing, X.-X., & Zuo, X.-N. (2015). A Connectome Computation System for discovery science of brain. Science Bulletin, 60(1), 86-95. doi:10.1007/s11434-014-0698-3Desikan, R. S., Ségonne, F., Fischl, B., Quinn, B. T., Dickerson, B. C., Blacker, D., … Killiany, R. J. (2006). An automated labeling system for subdividing the human cerebral cortex on MRI scans into gyral based regions of interest. NeuroImage, 31(3), 968-980. doi:10.1016/j.neuroimage.2006.01.021Cole, M. W., Yang, G. J., Murray, J. D., Repovš, G., & Anticevic, A. (2016). Functional connectivity change as shared signal dynamics. Journal of Neuroscience Methods, 259, 22-39. doi:10.1016/j.jneumeth.2015.11.011Smith, S. M., Jenkinson, M., Woolrich, M. W., Beckmann, C. F., Behrens, T. E. J., Johansen-Berg, H., … Matthews, P. M. (2004). Advances in functional and structural MR image analysis and implementation as FSL. NeuroImage, 23, S208-S219. doi:10.1016/j.neuroimage.2004.07.051Jenkinson, M., Beckmann, C. F., Behrens, T. E. J., Woolrich, M. W., & Smith, S. M. (2012). FSL. NeuroImage, 62(2), 782-790. doi:10.1016/j.neuroimage.2011.09.015Winkler, A. M., Ridgway, G. R., Webster, M. A., Smith, S. M., & Nichols, T. E. (2014). Permutation inference for the general linear model. NeuroImage, 92, 381-397. doi:10.1016/j.neuroimage.2014.01.060Bhaumik, R., Pradhan, A., Das, S., & Bhaumik, D. K. (2018). Predicting Autism Spectrum Disorder Using Domain-Adaptive Cross-Site Evaluation. Neuroinformatics, 16(2), 197-205. doi:10.1007/s12021-018-9366-0Cavanna, A. E., & Trimble, M. R. (2006). The precuneus: a review of its functional anatomy and behavioural correlates. Brain, 129(3), 564-583. doi:10.1093/brain/awl004Rolls, E. T. (2004). The functions of the orbitofrontal cortex. Brain and Cognition, 55(1), 11-29. doi:10.1016/s0278-2626(03)00277-xBeer, J. S., John, O. P., Scabini, D., & Knight, R. T. (2006). Orbitofrontal Cortex and Social Behavior: Integrating Self-monitoring and Emotion-Cognition Interactions. Journal of Cognitive Neuroscience, 18(6), 871-879. doi:10.1162/jocn.2006.18.6.871Li, W., Qin, W., Liu, H., Fan, L., Wang, J., Jiang, T., & Yu, C. (2013). Subregions of the human superior frontal gyrus and their connections. NeuroImage, 78, 46-58. doi:10.1016/j.neuroimage.2013.04.011Di Martino, A., O’Connor, D., Chen, B., Alaerts, K., Anderson, J. S., Assaf, M., … Milham, M. P. (2017). Enhancing studies of the connectome in autism using the autism brain imaging data exchange II. Scientific Data, 4(1). doi:10.1038/sdata.2017.1

Multivariate Six Sigma: A Case Study in Industry 4.0

[EN] The complex data characteristics collected in Industry 4.0 cannot be efficiently handled by classical Six Sigma statistical toolkit based mainly in least squares techniques. This may refrain people from using Six Sigma in these contexts. The incorporation of latent variables-based multivariate statistical techniques such as principal component analysis and partial least squares into the Six Sigma statistical toolkit can help to overcome this problem yielding the Multivariate Six Sigma: a powerful process improvement methodology for Industry 4.0. A multivariate Six Sigma case study based on the batch production of one of the star products at a chemical plant is presented.Palací-López, D.; Borràs-Ferrís, J.; Da Silva De Oliveria, LT.; Ferrer, A. (2020). Multivariate Six Sigma: A Case Study in Industry 4.0. Processes. 8(9):1-20. https://doi.org/10.3390/pr8091119S12089Linderman, K., Schroeder, R. G., Zaheer, S., & Choo, A. S. (2002). Six Sigma: a goal-theoretic perspective. Journal of Operations Management, 21(2), 193-203. doi:10.1016/s0272-6963(02)00087-6Grima, P., Marco-Almagro, L., Santiago, S., & Tort-Martorell, X. (2013). Six Sigma: hints from practice to overcome difficulties. Total Quality Management & Business Excellence, 25(3-4), 198-208. doi:10.1080/14783363.2013.825101Reis, M., & Gins, G. (2017). Industrial Process Monitoring in the Big Data/Industry 4.0 Era: from Detection, to Diagnosis, to Prognosis. Processes, 5(4), 35. doi:10.3390/pr5030035Ferrer, A. (2007). Multivariate Statistical Process Control Based on Principal Component Analysis (MSPC-PCA): Some Reflections and a Case Study in an Autobody Assembly Process. Quality Engineering, 19(4), 311-325. doi:10.1080/08982110701621304Peruchi, R. S., Rotela Junior, P., Brito, T. G., Paiva, A. P., Balestrassi, P. P., & Mendes Araujo, L. M. (2020). Integrating Multivariate Statistical Analysis Into Six Sigma DMAIC Projects: A Case Study on AISI 52100 Hardened Steel Turning. IEEE Access, 8, 34246-34255. doi:10.1109/access.2020.2973172Ismail, A., Bahri Mohamed, S., Juahir, H., Ekhwan Toriman, M., Md. Kassim, A., Md Zain, S., … Yang, C. (2018). DMAIC Six Sigma Methodology in Petroleum Hydrocarbon Oil Classification. International Journal of Engineering & Technology, 7(3.14), 98. doi:10.14419/ijet.v7i3.14.16868Jaeckle, C. M., & Macgregor, J. F. (1998). Product design through multivariate statistical analysis of process data. AIChE Journal, 44(5), 1105-1118. doi:10.1002/aic.690440509Höskuldsson, A. (1988). PLS regression methods. Journal of Chemometrics, 2(3), 211-228. doi:10.1002/cem.1180020306Wold, S., Sjöström, M., & Eriksson, L. (2001). PLS-regression: a basic tool of chemometrics. Chemometrics and Intelligent Laboratory Systems, 58(2), 109-130. doi:10.1016/s0169-7439(01)00155-1De Mast, J., & Lokkerbol, J. (2012). An analysis of the Six Sigma DMAIC method from the perspective of problem solving. International Journal of Production Economics, 139(2), 604-614. doi:10.1016/j.ijpe.2012.05.035Tomba, E., Facco, P., Bezzo, F., & Barolo, M. (2013). Latent variable modeling to assist the implementation of Quality-by-Design paradigms in pharmaceutical development and manufacturing: A review. International Journal of Pharmaceutics, 457(1), 283-297. doi:10.1016/j.ijpharm.2013.08.074Wold, S., Esbensen, K., & Geladi, P. (1987). Principal component analysis. Chemometrics and Intelligent Laboratory Systems, 2(1-3), 37-52. doi:10.1016/0169-7439(87)80084-9Abdi, H., & Williams, L. J. (2010). Principal component analysis. Wiley Interdisciplinary Reviews: Computational Statistics, 2(4), 433-459. doi:10.1002/wics.101Bro, R., & Smilde, A. K. (2014). Principal component analysis. Anal. Methods, 6(9), 2812-2831. doi:10.1039/c3ay41907jTomba, E., Barolo, M., & García-Muñoz, S. (2012). General Framework for Latent Variable Model Inversion for the Design and Manufacturing of New Products. Industrial & Engineering Chemistry Research, 51(39), 12886-12900. doi:10.1021/ie301214cKourti, T., & MacGregor, J. F. (1996). Multivariate SPC Methods for Process and Product Monitoring. Journal of Quality Technology, 28(4), 409-428. doi:10.1080/00224065.1996.11979699Geladi, P., & Kowalski, B. R. (1986). Partial least-squares regression: a tutorial. Analytica Chimica Acta, 185, 1-17. doi:10.1016/0003-2670(86)80028-9Barker, M., & Rayens, W. (2003). Partial least squares for discrimination. Journal of Chemometrics, 17(3), 166-173. doi:10.1002/cem.785Wold, S., Kettaneh-Wold, N., MacGregor, J. F., & Dunn, K. G. (2009). Batch Process Modeling and MSPC. Comprehensive Chemometrics, 163-197. doi:10.1016/b978-044452701-1.00108-3Nomikos, P., & MacGregor, J. F. (1995). Multivariate SPC Charts for Monitoring Batch Processes. Technometrics, 37(1), 41-59. doi:10.1080/00401706.1995.10485888Wold, S., Kettaneh, N., Fridén, H., & Holmberg, A. (1998). Modelling and diagnostics of batch processes and analogous kinetic experiments. Chemometrics and Intelligent Laboratory Systems, 44(1-2), 331-340. doi:10.1016/s0169-7439(98)00162-2Kourti, T. (2003). Abnormal situation detection, three-way data and projection methods; robust data archiving and modeling for industrial applications. Annual Reviews in Control, 27(2), 131-139. doi:10.1016/j.arcontrol.2003.10.004González-Martínez, J. M., de Noord, O. E., & Ferrer, A. (2014). Multisynchro: a novel approach for batch synchronization in scenarios of multiple asynchronisms. Journal of Chemometrics, 28(5), 462-475. doi:10.1002/cem.2620Kassidas, A., MacGregor, J. F., & Taylor, P. A. (1998). Synchronization of batch trajectories using dynamic time warping. AIChE Journal, 44(4), 864-875. doi:10.1002/aic.690440412Camacho, J., Pérez-Villegas, A., Rodríguez-Gómez, R. A., & Jiménez-Mañas, E. (2015). Multivariate Exploratory Data Analysis (MEDA) Toolbox for Matlab. Chemometrics and Intelligent Laboratory Systems, 143, 49-57. doi:10.1016/j.chemolab.2015.02.016González-Martínez, J. M., Camacho, J., & Ferrer, A. (2018). MVBatch: A matlab toolbox for batch process modeling and monitoring. Chemometrics and Intelligent Laboratory Systems, 183, 122-133. doi:10.1016/j.chemolab.2018.11.00

TiO2 Nanostructures for Photoelectrocatalytic Degradation of Acetaminophen

Advanced oxidation processes driven by renewable energy sources are gaining attention in degrading organic pollutants in waste waters in an efficient and sustainable way. The present work is focused on a study of TiO2 nanotubes as photocatalysts for photoelectrocatalytic (PEC) degradation of acetaminophen (AMP) at different pH (3, 7, and 9). In particular, different TiO2 photocatalysts were synthetized by stirring the electrode at different Reynolds numbers (Res) during electrochemical anodization. The morphology of the photocatalysts and their crystalline structure were evaluated by field emission scanning electron microscopy (FESEM) and Raman confocal laser microscopy (RCLM). These analyses revealed that anatase TiO2 nanotubes were obtained after anodization. In addition, photocurrent densities versus potential curves were performed in order to characterize the electrochemical properties of the photocatalysts. These results showed that increasing the Re during anodization led to an enhancement in the obtained photocurrents, since under hydrodynamic conditions part of the initiation layer formed over the tubes was removed. PEC degradation of acetaminophen was followed by ultraviolet-visible absorbance measurements and chemical oxygen demand tests. As drug mineralization was the most important issue, total organic carbon measurements were also carried out. The statistical significance analysis established that acetaminophen PEC degradation improved as hydrodynamic conditions linearly increased in the studied range (Re from 0 to 600). Additionally, acetaminophen conversion had a quadratic behavior with respect to the reaction pH, where the maximum conversion value was reached at pH 3. However, in this case, the diversity of the byproducts increased due to a different PEC degradation mechanism

PLATERO: A calibration protocol for plate reader green fluorescence measurements

One of the most common sources of information in Synthetic Biology is the data coming from plate reader fluorescence measurements. These experiments provide a measure of the light emitted by a certain fluorescent molecule, such as the Green Fluorescent Protein (GFP). However, these measurements are generally expressed in arbitrary units and are affected by the measurement device gain. This limits the range of measurements in a single experiment and hampers the comparison of results among experiments. In this work, we describe PLATERO, a calibration protocol to express fluorescence measures in concentration units of a reference fluorophore. The protocol removes the gain effect of the measurement device on the acquired data. In addition, the fluorescence intensity values are transformed into units of concentration using a Fluorescein calibration model. Both steps are expressed in a single mathematical expression that returns normalized, gain-independent, and comparable data, even if the acquisition was done at different device gain levels. Most important, the PLATERO embeds a Linearity and Bias Analysis that provides an assessment of the uncertainty of the model estimations, and a Reproducibility and Repeatability analysis that evaluates the sources of variability originating from the measurements and the equipment. All the functions used to build the model, exploit it with new data, and perform the uncertainty and variability assessment are available in an open access repository

Effect of Reynolds number and lithium cation insertion on titanium anodization

This work studies the influence of using hydrodynamic conditions (Reynolds number, Re = 0 to Re = 600) during Ti anodization and Li+ intercalation on anatase TiO2 nanotubes. The synthesized photocatalysts were characterized by using Field Emission Scanning Electron Microscope (FE-SEM), Raman Confocal Laser Microscopy, Electrochemical Impedance Spectroscopy (EIS), Mott-Schottky analysis (M-S), photoelectrochemical hydrogen production and resistance to photocorrosion tests. The obtained results showed that the conductivity of the NTs increases with Li+ intercalation and Re. The latter is due to the fact that the hydrodynamic conditions eliminate part of the initiation layer formed over the tube-tops, which is related to an increase of the photocurrent in the photoelectrochemical water splitting. Besides, the photogenerated electron-hole pairs are facilitated by Li+ intercalation. Finally, this work confirms that there is a synergistic effect between Re and Li+ intercalation

Controlled hydrodynamic conditions on the formation of iron oxide nanostructures synthesized by electrochemical anodization: Effect of the electrode rotation speed

Iron oxide nanostructures are of particular interest because they can be used as photocatalysts in water splitting due to their advantageous properties. Electrochemical anodization is one of the best techniques to synthesize nanostructures directly on the metal substrate (direct back contact). In the present study, a novel methodology consisting of the anodization of iron under hydrodynamic conditions is carried out in order to obtain mainly hematite (α-Fe2O3) nanostructures to be used as photocatalysts for photoelectrochemical water splitting applications. Different rotation speeds were studied with the aim of evaluating the obtained nanostructures and determining the most attractive operational conditions. The synthesized nanostructures were characterized by means of Raman spectroscopy, Field Emission Scanning Electron Microscopy, photoelectrochemical water splitting, stability against photocorrosion tests, Mott-Schottky analysis, Electrochemical Impedance Spectroscopy (EIS) and band gap measurements. The results showed that the highest photocurrent densities for photoelectrochemical water splitting were achieved for the nanostructure synthesized at 1000 rpm which corresponds to a nanotubular structure reaching ∼0.130 mA cm−2 at 0.54 V (vs. Ag/AgCl). This is in agreement with the EIS measurements and Mott-Schottky analysis which showed the lowest resistances and the corresponding donor density values, respectively, for the nanostructure anodized at 1000 rpm

Análisis de conectividad cerebral funcional entre pares de regiones anatómicas para caracterizar las alteraciones causadas por el trastorno del espectro autista a partir de imágenes de resonancia magnética

[ES] El trastorno del espectro autista (TEA) se define como una patología con tres características fundamentales: trastorno de la relación, alteraciones en la comunicación y falta de flexibilidad mental y comportamental. Hasta la fecha su diagnóstico se reduce a un conjunto de pruebas clínicas y psicológicas subjetivas, lo que está motivando la búsqueda de biomarcadores objetivos sobre variaciones estructurales y funcionales en el cerebro. El objetivo de este Trabajo Fin de Grado es el estudio de las diferencias en conectividad funcional cerebral mediante el análisis de imágenes de RM funcional en estado de reposo (rs-fMRI) entre sujetos con autismo y sujetos controles. Para ello se estudiará la correlación total y parcial entre pares de señales de regiones anatómicas del cerebro. Existe una controversia entre diferentes estudios para los resultados obtenidos dentro de la ¿default mode network¿ (DMN), entre hiper o hipoconectividad funcional de los sujetos con TEA. Las imágenes utilizadas han sido proporcionadas por la base de datos multicentro y pública ABIDE (Autism Brain Imaging Data Exchange). Los sujetos han sido emparejados por diversas variables demográficas y se han agrupado en tres rangos de edad (niños, adolescentes y adultos), para estudiar el TEA desde un punto de vista del desarrollo. Se han encontrado hipoconectividades funcionales de los sujetos con autismo respecto a los controles en regiones pertenecientes a la DMN. En niños entre la zona del giro temporal medio (parte anterior) izquierda y la parte derecha del lóbulo frontal (p = 0,0080), también en el córtex orbitofrontal izquierdo y el giro frontal superior derecho (p = 0,0144). En adolescentes entre el giro postcentral en ambos hemisferios cerebrales (p = 0,0012), además entre el córtex precúneo derecho y el giro temporal medio (parte anterior) derecho (p = 0,0236). Resultados que están en concordancia con los estudios de Assaf, Weng, Rudie y Mueller.[EN] Autism Spectrum Disorder (ASD) is defined as a pathology with three main characteristics: relationship disorder, alterations in communication, and lack of mental and behavioral flexibility. To date, its diagnose is based on some subjective medical and psychological tests. For that reason, the investigations are focused on the pursuit of objective biomarkers about structural and functional variations in the brain. The present work is based on the study of the variability in the cerebral functional connectivity by means of the analysis of functional RM images in resting state (rs-fMRI) among individuals with ASD and controls. For that, the connectivity among pairs of cerebral anatomical regions will be studied. There is a controversy in the results among different studies of the ¿default mode network¿ (DMN) about functional hyper or hypoconnectivity of the patients with ASD. The used images have been provided by the multicentre and public database ABIDE (Autism Brain Imaging Data Exchange). The patients have been paired by different demographic variables and they have been divided into three ages ranges (children, teenagers and adults), in order to study ASD from a development point of view. It has been found functional hypoconnectivities in patients with ASD in comparison with control subjects in these regions belonging to ¿default mode network¿ (DMN). In children, between left middle temporal gyrus (anterior part) and the right part of the frontal lobe (p = 0,0080), also in left orbitofrontal cortex and right superior frontal gyrus (p = 0,0144). In teenagers, between postcentral gyrus in both cerebral hemispheres (p = 0,0012), also between right precuneus and the middle right temporal gyrus (anterior part) (p = 0,0236). These results are in accordance with the studies of Assaf, Weng, Rudie and Mueller.[CAT/VA] El trastorn de l’espectre autista (TEA) es defineix com una patologia amb tres característiques fonamentals: trastorn de la relació, alteracions en la comunicació i falta de flexibilitat mental i comportamental. Fins ara el diagnòstic es redueix a un conjunt de probes clíniques i psicològiques subjectives, el que esta motivant la recerca de biomarcadors objectius sobre variacions estructurals i funcionals del cervell. L’objectiu d’aquest Treball Fi de Grau es l’estudi de les diferencies en connectivitat funcional cerebral mitjançant l’anàlisi d’imatges de RM funcional en estat de repòs (rs-fMRI) entre subjectes amb autisme i subjectes controls. Per a dur-ho a terme s’estudiarà la connectivitat total i parcial entre parells de senyals de regions anatòmiques del cervell. Existeix una controvèrsia entre diferents estudis per als resultats obtinguts dins de la “default mode network” (DMN), entre híper o hipoconnectivitat funcional dels subjectes amb TEA. Les imatges utilitzades han sigut proporcionades per la base de dades multicentre i pública ABIDE (Autism Brain Imaging Data Exchange). Els subjectes han sigut emparellats per diverses variables demogràfiques i s’han agrupat en tres rangs d’edat (xiquets, adolescents i adults), per estudiar el TEA des d’un punt de vista del desenvolupament. S’han trobat hipoconnectivitats funcionals dels subjectes amb autisme respecte als controls en regions pertanyents a la DMN. En xiquets entre la zona del gir temporal mitjà (part anterior) esquerre i la part dreta del lòbul frontal (p = 0,0080), també al còrtex orbitofrontal esquerre i el gir frontal superior dret (p = 0,0144). En adolescents entre el gir postcentral en els dos hemisferis cerebrals (p = 0,0012), a més entre el còrtex precúneo dret i el gir temporal mitjà (part anterior) dret (p = 0,0236). Resultats que estan en concordança amb els estudis d’Assaf, Weng, Rudie i Mueller.Borràs Ferrís, L. (2017). Análisis de conectividad cerebral funcional entre pares de regiones anatómicas para caracterizar las alteraciones causadas por el trastorno del espectro autista a partir de imágenes de resonancia magnética. http://hdl.handle.net/10251/89445.TFG

Estudio de la fotodegradación de paracetamol mediante nanotubos de TiO2

The use of renewable energies towards the degradation of organic pollutants in waste waters is a promising way in order to achieve sustainable development. The present work is focused on the study of TiO2 nanotubes, as photocatalyst, in a photoelectrochemical process for the degradation of paracetamol. In order to implement this process in the industry is necessary to improve the efficiency of the process. Therefore, it is essential the study of the hydrodynamic conditions during the electrochemical anodization of photocatalyst, since they have not been studied in detail, and also, the effect of the pH in the reaction medium was evaluated. This study has been carried out by using different techniques of characterization. The morphology of the photocatalyst and its crystalline structure have been evaluated by using Field Emission Scanning Electron Microscopy (FE-SEM) and Raman Confocal Microscopy. Besides, water splitting tests have been performed in order to characterize the electrochemical properties of the photocatalyst. Finally, photoelectrochemical degradation of the paracetamol by means of absorbance measurements with an ultraviolet-visible spectrophotometer and Chemical Oxygen Demand (COD) tests made possible to study the grade of paracetamol mineralization. The statistic significance analysis stablishes that paracetamol degradation improve as hydrodynamic conditions linearly increase for the studied range: Reynolds 0 - Reynolds 600. Moreover, paracetamol conversion has a quadratic behavior respect to the reaction pH where the maximum conversion value is reached for pH 3. However, in this case, the diversity of the by products increases, so, it is recommended to use a pH 9. Finally, it is observed that COD measurements decrease as paracetamol degradation increases.El uso de energías renovables con el fin de degradar contaminantes orgánicos en aguas residuales resulta una vía prometedora hacia el desarrollo sostenible. El presente trabajo se centra en el estudio de nanotubos de TiO2, como fotocatalizadores, en un proceso fotoelectroquímico para la degradación de paracetamol. Para conseguir su implementación a nivel industrial es necesario mejorar la eficiencia del proceso. Por ello, se requiere estudiar las condiciones hidrodinámicas de flujo durante el anodizado electroquímico del fotocatalizador, ya que no han sido estudiadas con detalle a día de hoy y, además, se decide evaluar el efecto conjunto del pH inicial en el medio de reacción. El estudio detallado del trabajo ha sido posible mediante distintas técnicas de caracterización. La morfología del fotocatalizador y su estructura cristalina se han evaluado mediante la Microscopía Electrónica de Barrido de Emisión de Campo (FE-SEM) y la Microscopía Raman Confocal respectivamente. Además, se ha llevado a cabo el ensayo de la rotura de la molécula de agua para obtener una caracterización electroquímica del fotocatalizador. Finalmente, la degradación de paracetamol por vía fotoelectroquímica por medio del seguimiento de la absorbancia con un espectrofotómetro Ultravioleta ¿ Visible y la Demanda Química de Oxígeno (DQO) han permitido estudiar el grado de mineralización del paracetamol. El análisis de significancia estadística determina que la degradación del paracetamol mejora a medida que aumentan las condiciones hidrodinámicas de flujo de modo lineal para el rango de estudio: Reynolds 0 ¿ Reynolds 600. Asimismo, la conversión de paracetamol posee un comportamiento cuadrático respecto al pH del medio de reacción donde se alcanza el valor máximo de conversión para pH 3. No obstante, en este caso aumenta la diversidad de subproductos, por tanto, es preferible trabajar a pH 9. Finalmente, se observa que la DQO disminuye a medida que aumenta la degradación de paracetamol.L’ús d’energies renovables amb la finalitat de degradar contaminants orgànics en aigües residuals resulta una via prometedora per al desenvolupament sostenible. El present treball se centra en l’estudi de nanotubs de TiO2, com fotocatalitzadors, en un procés fotoelectroquímic per a la degradació de paracetamol. Per aconseguir la seua implementació a nivell industrial és necessari millorar l’eficàcia del procés. Per tant, es requereix estudiar les condicions hidrodinàmiques de flux durant l’anoditzat electroquímic del fotocatalizador, ja que no ha sigut estudiat amb detall a dia d’avui i, a més, es decideix avaluar l’efecte conjunt del pH inicial en el medi de reacció. L’estudi detallat del treball ha sigut possible mitjançant distintes tècniques de caracterització. La morfologia de fotocatalitzador i la seua estructura cristal·lina s’han avaluat mitjançant la Microscopia Electrònica de Rastreig d’Emissió de Camp (FE-SEM) i la Microscopia Raman Confocal respectivament. A més, s’ha dut a terme l’assaig de trencament de la molècula d’aigua per obtindre una caracterització electroquímica del fotocatalitzador. Finalment, la degradació de paracetamol per via fotoelectroquímica per mitjà del seguiment de l’absorbància amb un espectrofotòmetre Ultraviolat – Visible i la Demanda Química d’Oxigen (DQO) han permès estudiar el grau de mineralització del paracetamol. L’anàlisi de significança estadística determina que la degradació del paracetamol millora a mesura que augmenten les condicions hidrodinàmiques del flux de mode lineal per al rang d’estudi: Reynolds 0 – Reynolds 600. Tanmateix, la conversió del paracetamol posseeix un comportament quadràtic respecte al pH del mitjà de reacció on s’assoleix el valor màxim de conversió per a pH 3. No obstant, en aquest cas augmenta la diversitat de subproductes, per tant, és preferible treballar a pH 9. Finalment, s’observa que la DQO disminueix a mesura que augmenta la degradació de paracetamol.Borràs Ferrís, J. (2017). Estudio de la fotodegradación de paracetamol mediante nanotubos de TiO2. http://hdl.handle.net/10251/87394.TFG

Causal latent space-based models for scientific learning in Industry 4.0

[ES] La presente tesis doctoral está dedicada a estudiar, desarrollar y aplicar metodologías basadas en datos, fundamentadas en modelos estadísticos multivariantes de variables latentes, para abordar el paradigma del aprendizaje científico en el entorno de la Industria 4.0. Se pone especial énfasis en los modelos causales basados en variables latentes que utilizan tanto datos provenientes de un diseño de experimentos como, principalmente, datos provenientes del proceso de producción diario, es decir, datos históricos. La tesis está estructurada en cinco partes. La primera parte discute el paradigma del aprendizaje científico en el entorno de la Industria 4.0. Se destacan los objetivos de la tesis. Además, se presenta una descripción exhaustiva de los modelos basados en variables latentes, sobre los cuales se fundamentan las metodologías novedosas propuestas en esta tesis. En la segunda parte, se presentan las novedosas aportaciones metodológicas. En primer lugar, se muestra el potencial de PLS para analizar datos del DOE, con o sin datos faltantes. Posteriormente, el potencial de los modelos causales basados en variables latentes se centra en definir el espacio de diseño de la materia prima que proporciona garantía de calidad con un cierto nivel de confianza para los atributos críticos de calidad, junto con el desarrollo de un nuevo índice de capacidad multivariante basado en el espacio latente para clasificar y seleccionar proveedores para una materia prima particular utilizada en un proceso de fabricación. La tercera parte pretende abordar aplicaciones novedosas mediante modelos causales basados en variables latentes utilizando datos históricos. En primer lugar, se trata de su aplicación en el ámbito sanitario: la Pandemia COVID-19. En este contexto, se utiliza el uso de modelos basados en variables latentes para desarrollar una alternativa a los ensayos clínicos controlados con placebo. Luego, se utilizan modelos basados en variables latentes para optimizar procesos en el marco de aplicaciones industriales. La cuarta parte presenta una interfaz gráfica de usuario desarrollada en código Python que integra los métodos desarrollados con el objetivo de ser autoexplicativa y fácil de usar. Finalmente, la última parte discute la relevancia de esta disertación, incluyendo propuestas que merecen mayor investigación.[CA] Aquesta tesi doctoral està dedicada a estudiar, desenvolupar i aplicar metodologies basades en dades, fonamentades en models estadístics multivariants de variables latents, per abordar el paradigma de l'aprenentatge científic a l'entorn de la Indústria 4.0. Es posa un èmfasi especial en els models causals basats en variables latents que utilitzen tant; dades provinents d'un disseny d'experiments com, principalment, dades provinents del procés de producció diari, és a dir, dades històriques. La tesi està estructurada en cinc parts. A la primera part es discuteix el paradigma de l'aprenentatge científic a l'entorn de la Indústria 4.0. Es destaquen els objectius de la tesi. A més, es presenta una descripció exhaustiva dels models basats en variables latents, sobre els quals es fonamenten les noves metodologies proposades en aquesta tesi. A la segona part, es presenten les noves aportacions metodològiques. En primer lloc, es mostra el potencial de PLS per analitzar dades del DOE, amb dades faltants o sense aquestes. Posteriorment, el potencial dels models causals basats en variables latents se centra a definir l'espai de disseny de la matèria prima que proporciona garantia de qualitat amb un cert nivell de confiança per als atributs crítics de qualitat, juntament amb el desenvolupament d'un nou índex de capacitat multivariant basat en l'espai latent per a classificar i seleccionar proveïdors per a una primera matèria particular utilitzada en un procés de fabricació. La tercera part pretén abordar aplicacions noves mitjançant models causals basats en variables latents utilitzant dades històrques. En primer lloc, es tracta de la seva aplicació a l'àmbit sanitari: la Pandèmia COVID-19. En aquest context, es fa servir l'ús de models basats en variables latents per desenvolupar una alternativa als assaigs clínics controlats amb placebo. Després s'utilitzen models basats en variables latents per optimitzar processos en el marc d'aplicacions industrials. La quarta part presenta una interfície gràfica d'usuari desenvolupada en codi Python que integra els mètodes desenvolupats amb l'objectiu de ser autoexplicativa i fàcil d'usar. Finalment, l'última part discuteix la rellevància d'aquesta dissertació, incloent-hi propostes que mereixen més investigació.[EN] The present Ph.D. thesis is devoted to studying, developing, and applying data-driven methodologies, based on multivariate statistical models of latent variables, to address the scientific learning paradigm in the Industry 4.0 environment. Particular emphasis is placed on causal latent variable-based models using both data coming from a planned design of experiments and, mainly, data coming from the daily production process, namely happenstance data. The dissertation is structured in five parts. The first part discusses the scientific learning paradigm in the Industry 4.0 environment. The objectives of the thesis are highlighted. In addition to that, a comprehensive description of latent variable-based models is presented, on which the novel methodologies proposed in this thesis are founded. In the second part, the novel methodological contributions are presented. Firstly, the potential of PLS to analyze data from DOE, with or without missing runs is illustrated. Then, the potential of causal latent variable-based models is concentrated on defining the raw material design space providing assurance of quality with a certain confidence level for the critical to quality attributes, jointly with the development of a novel latent space-based multivariate capability index to rank and select suppliers for a particular raw material used in a manufacturing process. The third part aims to address novel applications by means of causal latent variable-based models using happenstance data. First, it concerns a health application: the Pandemic COVID-19. In this context, the use of latent variable-based models is applied to develop an alternative to placebo-controlled clinical trials. Then, latent variable-based models are used to optimize processes within the framework of industrial applications. The fourth part introduces a graphical user interface developed in Python code that integrates the developed methods with the aim of being self-explanatory and user-friendly. Finally, the last part discusses the relevance of this dissertation, including proposals that deserve further research.Borràs Ferrís, J. (2023). Causal latent space-based models for scientific learning in Industry 4.0 [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/19899