Triple vasodilator therapy in pulmonary arterial hypertension associated with congenital heart disease.

OBJECTIVE: This study assessed the long-term effects of triple therapy with prostanoids on patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD), as there is limited information on the safety and efficacy of this treatment approach. METHODS: A retrospective cohort study was conducted on patients with PAH-CHD who were actively followed up at our centre. All patients were already receiving dual combination therapy at maximum doses. Clinical characteristics, including functional class (FC), 6-minute walking test distance (6MWTD) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, were documented before initiating triple therapy and annually for a 2-year follow-up period. RESULTS: A total of 60 patients were included in the study, with a median age of 41 years and 68% being women. Of these, 32 had Eisenmenger syndrome, 9 had coincidental shunts, 18 had postoperative PAH and 1 had a significant left-to-right shunt. After 1 year of triple combination initiation, a significant improvement in 6MWTD was observed (406 vs 450; p=0.0027), which was maintained at the 2-year follow-up. FC improved in 79% of patients at 1 year and remained stable in 76% at 2 years. NT-proBNP levels decreased significantly by 2 years, with an average reduction of 199 ng/L. Side effects were experienced by 33.3% of patients but were mostly mild and manageable. Subgroup analysis showed greater benefits in patients without Eisenmenger syndrome and those with pre-tricuspid defects. CONCLUSIONS: Triple therapy with prostanoids is safe and effective for patients with PAH-CHD, improving FC, 6MWTD and NT-proBNP levels over 2 years. The treatment is particularly beneficial for patients with pre-tricuspid defects and non-Eisenmenger PAH-CHD.

Outcomes of transcatheter pulmonary SAPIEN 3 valve implantation: an international registry.

BACKGROUND AND AIMS: Transcatheter pulmonary valve implantation (TPVI) is indicated to treat right-ventricular outflow tract (RVOT) dysfunction related to congenital heart disease (CHD). Outcomes of TPVI with the SAPIEN 3 valve that are insufficiently documented were investigated in the EUROPULMS3 registry of SAPIEN 3-TPVI. METHODS: Patient-related, procedural, and follow-up outcome data were retrospectively assessed in this observational cohort from 35 centres in 15 countries. RESULTS: Data for 840 consecutive patients treated in 2014-2021 at a median age of 29.2 (19.0-41.6) years were obtained. The most common diagnosis was conotruncal defect (70.5%), with a native or patched RVOT in 50.7% of all patients. Valve sizes were 20, 23, 26, and 29 mm in 0.4%, 25.5%, 32.1%, and 42.0% of patients, respectively. Valve implantation was successful in 98.5% [95% confidence interval (CI), 97.4%-99.2%] of patients. Median follow-up was 20.3 (7.1-38.4) months. Eight patients experienced infective endocarditis; 11 required pulmonary valve replacement, with a lower incidence for larger valves (P = .009), and four experienced pulmonary valve thrombosis, including one who died and three who recovered with anticoagulation. Cumulative incidences (95%CI) 1, 3, and 6 years after TPVI were as follows: infective endocarditis, 0.5% (0.0%-1.0%), 0.9% (0.2%-1.6%), and 3.8% (0.0%-8.4%); pulmonary valve replacement, 0.4% (0.0%-0.8%), 1.3% (0.2%-2.4%), and 8.0% (1.2%-14.8%); and pulmonary valve thrombosis, 0.4% (0.0%-0.9%), 0.7% (0.0%-1.3%), and 0.7% (0.0%-1.3%), respectively. CONCLUSIONS: Outcomes of SAPIEN 3 TPVI were favourable in patients with CHD, half of whom had native or patched RVOTs.

Geographical origin identification of mandarin fruits by analyzing fingerprint signatures based on multielemental composition.

Given rising traders and consumers concerns, the global food industry is increasingly demanding authentic and traceable products. Consequently, there is a heightened focus on verifying geographical authenticity as food quality assurance. In this work, we assessed pattern recognition approaches based on elemental predictors to discern the provenance of mandarin juices from three distinct citrus-producing zones located in the Northeast region of Argentina. A total of 202 samples originating from two cultivars were prepared through microwave-assisted acid digestion and analyzed by microwave plasma atomic emission spectroscopy (MP-AES). Later, we applied linear discriminant analysis (LDA), k-nearest neighbor (k-NN), support vector machine (SVM), and random forest (RF) to the element data obtained. SVM accomplished the best classification performance with a 95.1% success rate, for which it was selected for citrus samples authentication. The proposed method highlights the capability of mineral profiles in accurately identifying the genuine origin of mandarin juices. By implementing this model in the food supply chain, it can prevent mislabeling fraud, thereby contributing to consumer protection.

Genetic diversity and structure in two epiphytic orchids from the montane forests of southern Ecuador: The role of overcollection on Masdevallia rosea in comparison with the widespread Pleurothallis lilijae.

Ecuador has a high diversity of orchids, but little is known about levels of genetic diversity for the great majority of species. Understanding how orchids might adapt to changes is crucial as deforestation and fragmentation of forest ecosystems threaten the survival of many epiphytic orchids that depend on other species, such as fungi and their host trees, for germination, growth, and establishment. Overcollection and the illegal trade are also major concerns for the survival of wild populations of orchids. Despite increasing awareness, effective interventions are often limited by a lack of data concerning the impacts that overexploitation might have. To fill this gap, we tested the effects of overcollection in the genetic diversity and structure of Masdevallia rosea, a narrow distributed epiphytic orchid historically collected in Ecuador, in comparison with the widely distributed Pleurothallis lilijae. Genotyping based on AFLPs showed reduced levels of diversity in wild populations but most especially in the overcollected, M. rosea. Overall, genetic admixture was high in P. lilijae segregating populations by altitude levels while fewer genetic groups were found in M. rosea. Genetic differentiation was low in both species. A spatial genetic structure was found in P. lilijae depending on altitude levels, while no spatial genetic structure was found in M. rosea. These results suggest different scenarios for the two species: while gene flow over long distance is possible in P. lilijae, the same seems to be unlikely in M. rosea possibly due to the low levels of individuals in the known populations. In situ and ex situ conservation strategies should be applied to protect the genetic pool in these epiphytic orchid species, and to promote the connectivity between wild populations. Adopting measures to reduce overexploitation and to understand the impacts of harvesting in wild populations are necessary to strengthen the legal trade of orchids.

Measuring trace element fingerprinting for cereal bar authentication based on type and principal ingredient.

This paper introduces a method for determining the authenticity of commercial cereal bars based on trace element fingerprints. In this regard, 120 cereal bars were prepared using microwave-assisted acid digestion and the concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Se, Sn, Sr, V, and Zn were later measured by ICP-MS. Results confirmed the suitability of the analyzed samples for human consumption. Multielemental data underwent autoscaling preprocessing for then applying PCA, CART, and LDA to input data set. LDA model accomplished the highest classification modeling performance with a success rate of 92%, making it the suitable model for reliable cereal bar prediction. The proposed method demonstrates the potential of trace element fingerprints in distinguishing cereal bar samples according to their type (conventional and gluten-free) and principal ingredient (fruit, yogurt, chocolate), thereby contributing to global efforts for food authentication.

Prenatal diagnosis of isolated coronary artery fistula: systematic review, analysis of perinatal prognostic factors and case report.

BACKGROUND: Isolated coronary artery fistula (CAF) is a rare entity in which evidence for both prognosis and need for perinatal treatment is lacking. We aim to evaluate the characteristics, evolution and perinatal outcomes of reported cases, including one from our center. MATERIAL AND METHODS: We performed a systematic review in Medline, Pubmed, and Embase databases for cohort studies or case series related to prenatally diagnosed isolated congenital CAF according to PRISMA guidelines. The search was restricted to articles published until January 2022, including a case report from our center. A descriptive analysis was performed, and perinatal characteristics were dichotomized by outcome (development of symptoms, as well as the need for surgery during the neonatal period). Strength of association between prenatal variables and outcome was evaluated through Odds Ratio. RESULTS: Only 27 cases of prenatal diagnosis of isolated CAF have been published, including our patient. Most had their origin in the right coronary artery (63%) and drained in the right ventricle (55.6%). Most cases (72%) developed progressive intrauterine dilation of the fistulous tract, which was usually associated with symptoms of cardiac overload, such as cardiomegaly (57.7%). Up to two-thirds of prenatally diagnosed patients developed heart failure symptoms in the neonatal period, and 84% required postnatal intervention. Prenatal diagnosis of both cardiomegaly and diastolic steal is associated with an OR of 52 and 41 of developing postnatal symptoms. CONCLUSION: Prenatal diagnosis of isolated CAF can be achieved with adequate tools and trained sonographers. The development of cardiomegaly and diastolic steal significantly increases the risk of developing postnatal symptoms.

Rice Labeling according to Grain Quality Features Using Laser-Induced Breakdown Spectroscopy.

Rice is an important source of nutrition and energy consumed around the world. Thus, quality inspection is crucial for protecting consumers and increasing the rice's value in the productive chain. Currently, methods for rice labeling depending on grain quality features are based on image and/or visual inspection. These methods have shown subjectivity and inefficiency for large-scale analyses. Laser-induced breakdown spectroscopy (LIBS) is an analytical technique showing attractive features due to how quick the analysis can be carried out and its capability of providing spectra that are true fingerprints of the sample's elemental composition. In this work, LIBS performance was evaluated for labeling rice according to grain quality features. The LIBS spectra of samples with their grain quality numerically described as Type 1, 2, and 3 were measured. Several spectral processing methods were evaluated when modeling a k-nearest neighbors (k-NN) classifier. Variable selection was also carried out by principal component analysis (PCA), and then the optimal k-value was selected. The best result was obtained by applying spectrum smoothing followed by normalization by using the first fifteen principal components (PCs) as input variables and k = 9. Under these conditions, the method showed excellent performance, achieving sample classification with 94% overall prediction accuracy. The sensitivities ranged from 90 to 100%, and specificities were in the range of 92-100%. The proposed method has remarkable characteristics, e.g., analytical speed and analysis guided by chemical responses; therefore, the method is not susceptible to subjectivity errors.

Análisis histórico tendencial del proceso de formación del componente investigativo en la carrera de Medicina / Historical trend analysis of the formation process of the investigative component in the Medicine career

RESUMEN Introducción: dada la complejidad creciente de los problemas de salud de la población, se hace imprescindible perfeccionar el componente investigativo en los futuros médicos para asumir este reto y actuar en correspondencia con el contexto. Objetivo: describir las tendencias que han caracterizado el proceso formativo del componente investigativo en la carrera de Medicina. Métodos: se realizó una investigación cualitativa con enfoque histórico, a partir de la revisión documental, el método cronológico y la utilización de informantes clave, como métodos predominantes para desarrollar el objetivo de este estudio. Resultados: la sistematización teórica realizada posibilitó la determinación de los hitos histórico-pedagógicos para describir los indicadores asumidos, su progreso en cada una de las etapas y dilucidar las tendencias que han caracterizado dicho proceso. Discusión: el proceso de formación del componente investigativo en la carrera de Medicina ha ido en ascenso con el perfeccionamiento de los planes y programas de estudio. Sin embargo aún persisten insuficiencias, dada entre otros factores por la no acertada proyección desde las ciencias básicas biomédicas, para comunicar los resultados de la actividad investigativa del estudiante, con el uso de las tecnologías disponibles en correspondencia con el contexto.

ABSTRACT Introduction: given the growing complexity of the health problems of the population, it is essential to improve the research component in future doctors to take on this challenge and act in correspondence with the context. Objective: to refer to the trends that has characterized the training process of the research component in the Medicine career. Methods: a qualitative research with a historical approach was carried out, based on the documentary review, the chronological sub-method and the use of key informants, as predominant methods to develop the objective of this study. Results: the theoretical systematization carried out made it possible to determine the historical-pedagogical milestones to describe the assumed indicators, their progress in each of the stages and elucidate the trends that have characterized said process. Discussion: the formation process of the investigative component in the Medicine career has been on the rise with the improvement of the study plans and programs. However, insufficiencies still persist, given, among other factors, by the unsuccessful projection from the basic biomedical sciences, to communicate the results of the student's research activity, with the use of available technologies in correspondence with the context.

Scimitar syndrome and left pulmonary vein stenosis: A serious and rare association.

Scimitar syndrome is a rare constellation of cardiovascular anomalies consisting of partial right anomalous pulmonary venous drainage to the inferior vena cava, hypoplasia of the right lung, cardiac dextroposition, and in many cases, one or more aortopulmonary collaterals from the descending aorta to the hypoplastic lung. The "infantile form" commonly presents with significant heart failure and pulmonary hypertension. Stenosis of the left pulmonary veins associated with scimitar syndrome is a rare but well-described combination, usually associated with a poor prognosis. We describe two patients with this association in whom the left pulmonary vein stenosis manifested months after the initial diagnosis as a progressive lesion that complicated the course of the disease due to severe pulmonary hypertension. Both patients were successfully treated with a combination of surgical, percutaneous, and hybrid treatment.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Synthesis, Purification, and Characterization of Carbon Dots from Non-Activated and Activated Pyrolytic Carbon Black.

In this work, carbon dots were created from activated and non-activated pyrolytic carbon black obtained from waste tires, which were then chemically oxidized with HNO3. The effects caused to the carbon dot properties were analyzed in detail through characterization techniques such as ion chromatography; UV-visible, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy; ζ potential; transmission electron microscopy (TEM); and spectrofluorometry. The presence of functional groups on the surface of all carbon dots was revealed by UV-visible, FTIR, XPS, and Raman spectra. The higher oxidation degrees of carbon dots from activated precursors compared to those from nonactivated precursors resulted in differences in photoluminescence (PL) properties such as bathochromic shift, lower intensity, and excitation-dependent behavior. The results demonstrate that the use of an activating agent in the recovery of pyrolytic carbon black resulted in carbon dots with different PL properties. In addition, a dialysis methodology is proposed to overcome purification obstacles, finding that 360 h were required to obtain pure carbon dots synthesized by a chemical oxidation method.

Ciencias básicas en el proceso docente del técnico superior en Análisis Clínico y Medicina Transfusional / Basic sciences in the teaching process of the lab technician in Clinical Analysis and Transfusion Medicine

RESUMEN Fundamento: el diseño curricular debe partir de las exigencias sociales; este permite la determinación de las cualidades a alcanzar por el egresado y la estructura organizacional del proceso docente a nivel de carrera. Objetivo: valorar la importancia de las ciencias básicas en el plan del proceso docente del técnico superior en Análisis Clínico y Medicina Transfusional, por su influencia en la formación laboral del futuro egresado. Métodos: se realizó una investigación documental en el período comprendido entre septiembre y noviembre de 2019 en la Universidad de Ciencias Médicas de Camagüey. Se emplearon métodos teóricos: análisis-síntesis e inductivo-deductivo; y empíricos: el análisis documental a partir del cual se realizaron valoraciones cualitativa y cuantitativa del plan del proceso docente del técnico superior en Análisis Clínico y Medicina Transfusional. Resultados: en el plan del proceso docente de esta carrera no aparecen las asignaturas clasificadas por ciclos y se evidencia una disminución considerable del ciclo básico. Conclusiones: la valoración realizada evidencia que falta precisión del papel que juega cada ciclo de las asignaturas en el plan del proceso docente, lo que influye negativamente en su cientificidad y se demuestra que tiene una elevada carga laboral, ya que el estudiante desde sus primeros años se encuentra vinculado al trabajo diario en el servicio asistencial en el que adquiere habilidades propias de la profesión.

ABSTRACT Background: curricular design must start from social demands; this allows the determination of the qualities to be achieved by the graduate and the organizational structure of the teaching process at degree level. Objective: to assess the importance of basic sciences in the plan of the teaching process of the lab technician in Clinical Analysis and Transfusion Medicine, due to its influence on the job training of future graduates. Methods: a documentary research was carried out in the period from September to November 2019 at Camagüey University of Medical Sciences. Theoretical methods were used: analysis-synthesis and inductive-deductive; and empirical ones: the documentary analysis from which qualitative and quantitative evaluations were made of the plan of the teaching process of the lab technician in Clinical Analysis and Transfusion Medicine. Results: in the plan of the teaching process of this degree, the subjects classified by cycles do not appear and there is a considerable decrease in the basic cycle. Conclusions: the assessment carried out shows that there is a lack of precision in the role that each cycle of the subjects play in the plan of the teaching process, which negatively influences its scientific approach and shows that it has a high workload, since the student from its early years is linked to daily work in the healthcare service in which it acquires distinctive skills of the profession.

El Registro Público Cubano de Ensayos Clínicos desde la perspectiva de los estudios de Ciencia Tecnología y Sociedad / The Cuban Public Registry of Clinical Trials from the perspective of Science, Technology and Society studies

RESUMEN El presente artículo es el resultado de un estudio dirigido a demostrar la contribución del Registro Público Cubano de Ensayos Clínicos (RPCEC) en la transparencia de las publicaciones de investigaciones en seres humanos. Se realizó una revisión bibliográfica de diferentes fuentes de información científica en la biblioteca electrónica SciELO y otros sitios web con el objetivo de caracterizar el RPCEC desde una perspectiva de los estudios sociales de la Ciencia y la Tecnología. Se precisaron consideraciones sobre las temáticas en el momento de realizar la investigación. Se constató que el RPCEC es una tecnología informática que favorece la limpieza de los datos y su generalización, lo cual contribuye a eliminar el sesgo de publicación. Además, desde el punto de vista de la bioética promueve el desarrollo científico y la búsqueda efectiva en la sociedad contemporánea.

ABSTRACT This article is the result of a study aimed at demonstrating the contribution of the Cuban Public Registry of Clinical Trials (RPCEC) in the transparency of research publications on human beings. A bibliographic review of different sources of scientific information was carried out in the SciELO electronic library and other websites in order to characterize the RPCEC from a perspective of the social studies of Science and Technology. Considerations on the issues were required at the time of conducting the research. It was found that RPCEC is a computer technology that favors data cleaning and generalization, which helps to eliminate publication bias. Furthermore, from the point of view of bioethics, it promotes scientific development and effective research in contemporary society.

Sequential SEM-EDS, PLM, and MRS Microanalysis of Individual Atmospheric Particles: A Useful Tool for Assigning Emission Sources.

In this work, the particulate matter (PM) from three different monitoring stations in the Monterrey Metropolitan Area in Mexico were investigated for their compositional, morphological, and optical properties. The main aim of the research was to decipher the different sources of the particles. The methodology involved the ex situ sequential analysis of individual particles by three analytical techniques: scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), polarized light microscopy (PLM), and micro-Raman spectroscopy (MRS). The microanalysis was performed on samples of total suspended particles. Different morphologies were observed for particles rich in the same element, including prismatic, spherical, spheroidal, and irregular morphologies. The sequential microanalysis by SEM-EDS/PLM/MRS revealed that Fe-rich particles with spherical and irregular morphologies were derived from anthopogenic sources, such as emissions from the metallurgical industry and the wear of automobile parts, respectively. In contrast, Fe-rich particles with prismatic morphologies were associated with natural sources. In relation to carbon (C), the methodology was able to distinguish between the C-rich particles that came from different anthopogenic sources-such as the burning of fossil fuels, biomass, or charcoal-and the metallurgical industry. The optical properties of the Si-rich particles depended, to a greater extent, on their chemical composition than on their morphology, which made it possible to quickly and accurately differentiate aluminosilicates from quartz. The methodology demonstrated in this study was useful for performing the speciation of the particles rich in different elements. This differentiation helped to assign their possible emission sources.

Predictive Value of Immune Cell Functional Assay for Non-Cytomegalovirus Infection in Lung Transplant Recipients: A Multicenter Prospective Observational Study.

INTRODUCTION: Immune cell functional assay (ImmuKnow®) is a non-invasive method that measures the state of cellular immunity in immunosuppressed patients. We studied the prognostic value of the assay for predicting non-cytomegalovirus (CMV) infections in lung transplant recipients. METHODS: A multicenter prospective observational study of 92 patients followed up from 6 to 12 months after transplantation was performed. Immune cell functional assay was carried out at 6, 8, 10, and 12 months. RESULTS: Twenty-three patients (25%) developed 29 non-CMV infections between 6 and 12 months post-transplant. At 6 months, the immune response was moderate (ATP 225-525ng/mL) in 14 (15.2%) patients and low (ATP<225ng/mL) in 78 (84.8%); no patients had a strong response (ATP≥525ng/mL). Only 1 of 14 (7.1%) patients with a moderate response developed non-CMV infection in the following 6 months compared with 22 of 78 (28.2%) patients with low response, indicating sensitivity of 95.7%, specificity of 18.8%, positive predictive value (PPV) of 28.2%, and negative predictive value (NPV) of 92.9% (AUC 0.64; p=0.043). Similar acute rejection rates were recorded in patients with mean ATP≥225 vs. <225ng/mL during the study period (7.1% vs. 9.1%, p=0.81). CONCLUSION: Although ImmuKnow® does not seem useful to predict non-CMV infection, it could identify patients with a very low risk and help us define a target for an optimal immunosuppression.

Predictive Value of Immune Cell Functional Assay for Non-Cytomegalovirus Infection in Lung Transplant Recipients: A Multicenter Prospective Observational Study.

INTRODUCTION: Immune cell functional assay (ImmuKnow®) is a non-invasive method that measures the state of cellular immunity in immunosuppressed patients. We studied the prognostic value of the assay for predicting non-cytomegalovirus (CMV) infections in lung transplant recipients. METHODS: A multicenter prospective observational study of 92 patients followed up from 6 to 12 months after transplantation was performed. Immune cell functional assay was carried out at 6, 8, 10, and 12 months. RESULTS: Twenty-three patients (25%) developed 29 non-CMV infections between 6 and 12 months post-transplant. At 6 months, the immune response was moderate (ATP 225-525ng/mL) in 14 (15.2%) patients and low (ATP<225ng/mL) in 78 (84.8%); no patients had a strong response (ATP≥525ng/mL). Only 1 of 14 (7.1%) patients with a moderate response developed non-CMV infection in the following 6 months compared with 22 of 78 (28.2%) patients with low response, indicating sensitivity of 95.7%, specificity of 18.8%, positive predictive value (PPV) of 28.2%, and negative predictive value (NPV) of 92.9% (AUC 0.64; p=0.043). Similar acute rejection rates were recorded in patients with mean ATP≥225 vs. <225ng/mL during the study period (7.1% vs. 9.1%, p=0.81). CONCLUSION: Although ImmuKnow® does not seem useful to predict non-CMV infection, it could identify patients with a very low risk and help us define a target for an optimal immunosuppression.

Fundamentos teóricos para un estudio sobre la ludopatía / Theoretical foundations for a study on compulsive gambling

RESUMEN El presente texto hace referencia al uso de las nuevas tecnologías entre los adolescentes y jóvenes y al modo en que a nivel mundial llega a convertirse en una conducta adictiva, debido a su empleo inadecuado en esta población. Su objetivo está dirigido a fundamentar los elementos epistemológicos sobre la ludopatía para su atención. Se incursiona en cuestiones inherentes a las adicciones, la drogadicción y en particular sobre la ludopatía y sus consecuencias en los sujetos comprendidos entre las edades mencionadas. Este artículo constituye una salida del proyecto de investigación Sistema de estrategias educativas para la prevención de conductas adictivas en los adolescentes del área de salud Tula Aguilera, el cual gestiona el Centro para el Desarrollo de las Ciencias Sociales y Humanísticas en Salud, de la Universidad de Ciencias Médicas de Camagüey. El tipo de estudio es de carácter Investigación Desarrollo y se ejecutó en el período comprendido entre enero de 2017 y febrero de 2020.

ABSTRACT The present text makes reference to the use of the new technologies among the adolescents and young and to the way in that its inadequate employment at world level in the people, ends up becoming an addictive behavior. Their objective is directed to base the elements epistemológicos of the treatment of the ludopatía, from the school activity. This article constitutes an exit of the project of investigation System of educational strategies for the prevention of addictive behaviors in the adolescents of the area of health Tula Aerie, which negotiates the Center for the Development of the Social and Humanistic Sciences in Health, of the University of Medical Sciences of Camagüey. The study type is of character Investigation Development and it was executed in the period understood between January of 2017 and February of 2020.

Characterization of Chemically Activated Pyrolytic Carbon Black Derived from Waste Tires as a Candidate for Nanomaterial Precursor.

Pyrolysis is a feasible solution for environmental problems related to the inadequate disposal of waste tires, as it leads to the recovery of pyrolytic products such as carbon black, liquid fuels and gases. The characteristics of pyrolytic carbon black can be enhanced through chemical activation in order to produce the required properties for its application. In the search to make the waste tire pyrolysis process profitable, new applications of the pyrolytic solid products have been explored, such as for the fabrication of energy-storage devices and precursor in the synthesis of nanomaterials. In this study, waste tires powder was chemically activated using acid (H2SO4) and/or alkali (KOH) to recover pyrolytic carbon black with different characteristics. H2SO4 removed surface impurities more thoroughly, improving the carbon black's surface area, while KOH increased its oxygen content, which improved the carbon black's stability in water suspension. Pyrolytic carbon black was fully characterized by elemental analysis, inductively coupled plasma-optical emission spectrometry (ICP-OES), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), N2 adsorption/desorption, scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), dynamic light scattering (DLS), and ζ potential measurement. In addition, the pyrolytic carbon black was used to explore its feasibility as a precursor for the synthesis of carbon dots; synthesized carbon dots were analyzed preliminarily by SEM and with a fluorescence microplate reader, revealing differences in their morphology and fluorescence intensity. The results presented in this study demonstrate the effect of the activating agent on pyrolytic carbon black from waste tires and provide evidence of the feasibility of using waste tires for the synthesis of nanomaterials such as carbon dots.

Assessment of the Reduction in Vehicles Emissions by Implementing Inspection and Maintenance Programs.

To improve air quality in urban centers, vehicle Inspection and Maintenance (I/M) programs were created to identify highly polluting vehicles and force them to undergo mechanical maintenance. In this context, a methodology, based on a single measurement campaign using a Remote Sensing Device (RSD), is presented in this work to assess the reduction in vehicles emissions obtained from implementing I/M programs. As a case study, an RSD campaign was carried out in Mexico, specifically in Monterrey's Metropolitan Area (MMA). Approximately 0.4% of the vehicles registered in this region were sampled under similar conditions to those found in I/M programs. The results obtained suggested that 39% of the vehicles would not comply with the current national regulations for circulating vehicles. Following a conservative scenario, the implementation of a vehicle I/M program in this urban center has the potential of reducing the current mass emissions of HC, CO and NO in approximately 69%, 42% and 28%, respectively.