Correction to "Solvent Additive-Induced Deactivation of the Cu-ZnO(Al2O3)-Catalyzed γ-Butyrolactone Hydrogenolysis: A Rare Deactivation Process".

[This corrects the article DOI: 10.1021/acs.iecr.1c04080.].

Investigaciones en salud mental infanto-juvenil en Chile durante la pandemia de COVID-19: una revisión de alcance / d and youth mental health research in Chile during the COVID-19 pandemic: a scoping review

En todo el mundo se han descrito efectos negativos de la pandemia de COVID-19 en la salud mental, especialmente en la población infanto-juvenil. Sin embargo, en Chile, la investigación disponible aún no se ha sistematizado. El objetivo de este estudio fue revisar sistemáticamente las publicaciones científicas sobre salud mental infanto-juvenil en Chile durante la pandemia de COVID-19. Se buscaron reportes de investigación en las bases de datos WoS, Scopus, SciELO y LILACS. Se incluyeron 13 estudios que cumplieron los criterios de inclusión. Los estudios son heterogéneos en cuanto a sus objetivos e instrumentos utilizados. Varios estudios coinciden en que hay un aumento de los síntomas internalizantes, externalizantes y somáticos en la población infanto-juvenil desde la pandemia. Es necesario promover investigaciones colaborativas y longitudinales e investigaciones que evalúen la eficacia de intervenciones preventivas y terapéuticas. Estos resultados pueden ser útiles para clínicos, académicos y tomadores de decisión en políticas públicas para que puedan adoptar medidas para mejorar la salud mental de esta población. Palabras Clave: Salud mental, niños, adolescentes, jóvenes, COVID-19.

Abstract. Negative effects of the COVID-19 pandemic on mental health have been described worldwide, especially in the child and youth population. However, in Chile, the available research has not yet been systematized. This study aimed to systematically review scientific publications on child and youth mental health in Chile during the COVID-19 pandemic. The WoS, Scopus, SciELO, and LILACS databases were searched for research reports. Thirteen studies that met the inclusion criteria were included. The studies are heterogeneous in terms of their objectives and instruments used. Several studies agree that there is an increase in internalizing, externalizing, and somatic symptoms in the child and youth population since the pandemic. There is a need to promote collaborative and longitudinal research, and research that evaluates the efficacy of preventive and therapeutic interventions. These results may be useful to clinicians, academics, and public policymakers so that they can take steps to improve the mental health of this population. Keywords: Mental health, children, adolescents, youth, COVID-19.

A Simplified Kinetic Model for the Enantioselective Hydrogenation of 1-Phenyl-1,2-Propanedione over Ir/TiO2 in the Presence of a Chiral Additive.

This communication proposes a preliminary simplified kinetic model for the hydrogenation of 1-phenyl-1,2-propanedione that can render up to eight compounds, involving regioselectivity and enantioselectivity. The catalytic system comprises two functionalities; the heterogeneous catalyst (Ir/TiO2) plays the role for the hydrogenation, whereas the adsorption/binding to the active site is played by a chiral molecule (cinchonidine), added to the reaction mixture. The reaction occurs at room temperature and total pressure of 40 bar. The product distribution shows competitive parallel and series pathways with up to 12 possible reactions. Despite the complexity of both reaction and catalyst system, a simplified kinetic model was able to predict the concentrations profiles. The model assumes the reactions to be apparent first order in the concentrations of reactant and intermediate products, while the kinetic constants include all other effects (partial pressure of hydrogen, solvent and catalyst effects, and the concentration of the chiral additive). The concentration profiles were well-modeled with low residual values. The errors in the kinetic constants (k-values) were small for all relevant parameters of the main reaction pathways. Two k-values are nil, which is the lower bound imposed in the model, suggesting that these reaction pathways are likely negligible. The positive outcome from this simplified model suggests that the process can be formally treated as a first-order irreversible homogeneous catalyzed reaction, despite a heterogeneous catalyst was employed (with a modifier). Despite the promising results, the model must be extended for a more general applicability, or conditions where it is applicable.

Complex Crystallization Kinetics of a Mg-Al Hydrotalcite and Their Practical Implications from the Process Point of View.

Hydrotalcites are an important class of layered materials, displaying ion-exchange, adsorption, and base catalytic properties. The crystallization kinetics for hydrotalcites are however hardly available. Nevertheless, as their reconstruction from the oxides (also called as "memory effect") is considered a synthesis route, this can be used to study the crystallization phenomena. This note looks at the reconstruction kinetics of a Mg-Al hydrotalcite using previously reported kinetic expressions. It was found that high temperature is beneficial if the process is controlled by nucleation. The temperature effect is less obvious when the process reaches a diffusional control regime. For example, temperature is beneficial to shorten the processing time in a nucleation-regime conversion (e.g., 40%). However, to achieve a high conversion (e.g., 98-99%), an intermediate temperature shows the optimal condition, i.e., shortest processing time. The work shows useful side effects of diffusional control. It also highlights the importance of obtaining the kinetics over the entire range for process optimization and, finally, emphasizes that both parameters in the Avrami-Erofe'ev model impact the time required to achieve a given conversion. Directions for further studies to understand the kinetic-process relationships have been highlighted.

Solvent Additive-Induced Deactivation of the Cu-ZnO(Al2O3)-Catalyzed γ-Butyrolactone Hydrogenolysis: A Rare Deactivation Process.

This work reports initial results on the effect of low concentrations (ppm level) of a stabilizing agent (2,6-di-tert-butyl-4-methylphenol, BHT) present in an off-the-shelf solvent on the catalyst performance for the hydrogenolysis of γ-butyrolactone over Cu-ZnO-based catalysts. Tetrahydrofuran (THF) was employed as an alternative solvent in the hydrogenolysis of γ-butyrolactone. It was found that the Cu-ZnO catalyst performance using a reference solvent (1,4-dioxane) was good, meaning that the equilibrium conversion was achieved in 240 min, while a zero conversion was found when employing tetrahydrofuran. The deactivation was studied in more detail, arriving at the preliminary conclusion that one phenomenon seems to play a role: the poisoning effect of a solvent additive present at the ppm level (BHT) that appears to inhibit the reaction completely over a Cu-ZnO catalyst. The BHT effect was also visible over a commercial Cu-ZnO-MgO-Al2O3 catalyst but less severe than that over the Cu-ZnO catalyst. Hence, the commercial catalyst is more tolerant to the solvent additive, probably due to the higher surface area. The study illustrates the importance of solvent choice and purification for applications such as three-phase-catalyzed reactions to achieve optimal performance.

Correction: Temperature control in DRIFT cells used for in situ and operando studies: where do we stand today?

Correction for 'Temperature control in DRIFT cells used for in situ and operando studies: where do we stand today?' by Ignacio Melián-Cabrera, Phys. Chem. Chem. Phys., 2020, DOI: .

Temperature control in DRIFT cells used for in situ and operando studies: where do we stand today?

Vibrational spectroscopy is considered a workhorse in heterogeneous catalysis. This group of techniques has allowed an understanding of the structure of the solid catalysts, not only with ex situ methodologies but also with in situ and operando studies. In this perspective, an appraisal of diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) is provided, in particular regarding the heat transfer limitations in the cell, and solutions, which can affect the measurement, with consequences in kinetic studies.

Operando Study Reveals the Superior Cracking Activity and Stability of Hierarchical ZSM-5 Catalyst for the Cracking of Low-Density Polyethylene.

A new theoretical and practical framework has been developed through operando study of the zeolite catalytic cracking of low-density polyethylene (as a model reaction) under reaction conditions. Results show that microporous ZSM-5 gives rise to less cracking products. Hierarchical ZSM-5 zeolites are more active cracking catalysts, rendering more C2 -C5 hydrocarbons, with a delayed deactivation due to the secondary porosity. This tool in combination with thermogravimetric analysis provides complementary and valuable information for the study, and design of advanced catalysts.

En el Infarto agudo al miocardio los niveles plasmáticos de microvesículas extracelulares se elevan más precozmente que el aumento de la Troponina-I / Plasma levels of extracellular macrovesicles are elevated earlier than troponin-I in patients with myocardial infarction

Introducción: La Troponina I (TnI) plasmática es el biomarcador "Gold" estándar utilizado en diagnóstico de Infarto Agudo al Miocardio (IAM), indicando necrosis cardíaca. Las microvesículas extracelulares (MVEC), participan en comunicación celular, por lo que estudiar su distribución entregaría información respecto del evento isquémico, antesala del infarto. Objetivo: Estudiar las MVECs plasmáticas en pacientes con Síndrome Coronario Agudo (SCA) y compararlas con los niveles de TnI. Métodos: Plasma de 22 pacientes controles se recolectó 0-2hrs post-ingreso a urgencia. Plasma de 45 pacientes SCA se recolectó 0-2, 6-8 y 10-14hrs post ingreso, junto con la toma de muestra para estudio de TnI. Las MVECs plasmáticas fueron enriquecidas mediante kit comercial. La determinación de la concentración y tamaño MVECs se realizó por NTA (Nanoparticles Tracking Assay) usando el equipo Nanosight. Resultados: La concentración promedio de MVECs 0-2 hrs post ingreso fue 7,2 veces superior en plasma de pacientes con SCA vs controles y la moda del tamaño disminuyó en pacientes con SCA. La TnI no mostró diferencias significativas en 0-2 hrs post ingreso en el grupo estudiado. La concentración de las MVEC disminuyó significativamente después de 10-14 hrs post ingreso, mientras que la concentración promedio TnI se mantuvo invariable demostrando el aumento de MVECs previo al incremento de TnI. Conclusión. El aumento de MVECs previo al incremento de la TnI en pacientes infartados, sugiere que las MVECs aumentan en la fase previa del IAM, como respuesta al daño tisular. Actualmente, estudiamos el contenido molecular de las MVECs, para establecer un método diagnóstico del Síndrome Coronario Agudo basado en MVECs.

Background: Troponin I (TnI) is the gold standard used to establish the diagnosis of myocardial infarction (AMI), indicating the presence of myocardial necrosis. Extracellular micro vesicles are involved in cellular communication. Their distribution may provide information relating to the development of AMI in patients with acute coronary syndromes (ACS) Aim: to study plasma levels of ECMV compared to those of TnI in patients with ACS. Methods: The plasma levels of TnI and ECMV from 22 control patients coming to the emergency units was compared to plasma from 45 patients with ACS. Levels of both parameters were determined 0-2, 6-8 and 10-14 hours post admission. ECMVs were enriched by means of a commercial kit. Concentration and size of ECMV was determined by NTA (Nanoparticles tracking assay) using the Nanosight equipment. Results: Plasma concentration of ECMV was 7.2 times higher than that of TnI 0-2 hrs post admission. The mode of ECMV size was lower in patients with ACS. Concentration of ECMV had decreased significantly 10-14 hrs post admission, whereas the TnI levees remained stable. Conclusion: The increase in ECMV earlier than TnI in AMI suggests that ECMV are elevated in the pre-AMI phase, as a response to early tissue damage. A study of cellular content of ECMV, being carried out, may lead to develop a method for the early diagnosis of AMI in patients with ACS.

Trasplante simultáneo de riñón y páncreas exitoso en paciente con lipodistrofia parcial congénita / Successfull Simultaneous Pancreas Kidney transplantation in a patient with congenital partial lipodystrophy

No disponible

Reporte de dos casos clínicos de melanoma con metástasis cardíacas: ("dos caras de una misma moneda") / Melanoma with cardiac metastasis: report of two cases

A 39 year old man presented with signs of an ischemic in-farct in the territory of the medial cerebral artery. A large mobile mass was present in the left atrium and a biopsy showed tissue heavily infiltrated with fat and resection was not possible. A small lesion located at the dorsum allowed a histologic confirmation of a melanoma. The patient died 4 months after surgery. The second patient, a 34 year old woman being treated with chemotherapy for an ovarian melanoma was found to have a right atrial mass. After successful resection of the mass a metastasis of the original melanoma was confirmed and the patient remains in good condition at mid term follow up.

Base-free, one-pot chemocatalytic conversion of glycerol to methyl lactate using supported gold catalysts.

We report an efficient one-pot conversion of glycerol (GLY) to methyl lactate (MLACT) in methanol in good yields (73 % at 95 % GLY conversion) by using Au nanoparticles on commercially available ultra-stable zeolite-Y (USY) as the catalyst (160 °C, air, 47 bar pressure, 0.25 M GLY, GLY-to-Au mol ratio of 1407, 10 h). The best results were obtained with zeolite USY-600, a catalyst that has both Lewis and Brønsted sites. This methodology provides a direct chemo-catalytic route for the synthesis of MLACT from GLY. MLACT is stable under the reaction conditions, and the Au/USY catalyst was recycled without a decrease in the activity and selectivity.

Room temperature detemplation of zeolites through H2O2-mediated oxidation.

Detemplation of zeolite beta has been successfully achieved at low temperature by controlled oxidation of the template using H2O2 and catalyzed by traces of Fe3+. With this approach, unlike calcination, the pristine structure of the material is well preserved; no extra-framework aluminium is formed.