Current Overview of Corrosion Inhibition of API Steel in Different Environments.

API (American Petroleum Institute) steels are the most employed metal alloys in the oil industry due to their outstanding mechanical properties; however, their protection is considered as an imperative matter because of their corrosion damage vulnerability when exposed to different surroundings that provoke a rate increase in the concomitant redox reactions. This problematic situation becomes more relevant when the generation and/or use of one or various aqueous corrosive environments occur, in addition to process conditions, the result of which is extremely difficult to be controlled. For these reasons, the internal and external protection of exposed metallic systems are considered as a fundamental concern, where internal corrosion is often controlled through the addition of corrosion inhibitors (CIs). The present review analyzes researchers' contributions in the last years to the study and evaluation of CIs for API steel in different corrosive media featuring HCl, H2SO4, H3NSO3H, CO2, H2S, NaCl, and production water under different temperature and flow conditions. Different CIs derived from plant extracts, drugs, nanoparticles, or ionic liquids, mainly destined for acid media, were found. Throughout the review, an exhaustive analysis of inhibition process results is carried out based on gravimetric and/or electrochemical techniques that consider the weight loss of the metallic material and electrical behavior (current density, resistance, capacitance, frequency, impedance, etc.). Likewise, the results of computational analyses and those of surface analysis techniques were taken into account to reinforce the study of CIs.

Social media & subjectivity: Adolescent lived experiences with social media in a Southern California middle school.

The widespread use of social media (SM) platforms among adolescents has raised concerns over its role in increased adverse physical and mental health conditions. However, current research linking SM use with adolescent health relies on tenuous correlational associations, disproportionately focuses on harmful effects of its use, and seldom examines the perspectives of youth themselves (Odgers and Jensen, 2020; Schønning et al., 2020). This article examines adolescent lived experience in relation to SM platform engagement. Drawing from ethnographic fieldwork conducted in 2018-2019 and 2021-2022 among 75 middle-school adolescents living in an ethnically diverse and low-income Southern California community, we examine adolescent subjective experiences with SM platforms that illuminate adolescent concerns during this developmental stage. By attending to adolescent subjectivity, this article reveals the ways in which engagement with SM platforms is inextricable from cultural, social, political, and socio-emotional milieu.

Temperature Effect on the Corrosion Inhibition of Carbon Steel by Polymeric Ionic Liquids in Acid Medium.

In the present research work, the temperature effect on the corrosion inhibition process of API 5L X60 steel in 1 M H2SO4 by employing three vinylimidazolium poly(ionic liquid)s (PILs) was studied by means of electrochemical techniques, surface analysis and computational simulation. The results revealed that the maximal inhibition efficiency (75%) was achieved by Poly[VIMC4][Im] at 308 K and 175 ppm. The PILs showed Ecorr displacements with respect to the blank from -14 mV to -31 mV, which revealed the behavior of mixed-type corrosion inhibitors (CIs). The steel micrographs, in the presence and absence of PILs, showed less surface damage in the presence of PILs, thus confirming their inhibiting effect. The computational studies of the molecular orbitals and molecular electrostatic potential of the monomers suggested that the formation of a protecting film could be mainly due to the nitrogen and oxygen heteroatoms present in each structure.

Depression and anxiety among multiethnic middle school students: Age, gender, and sociocultural environment.

BACKGROUND: Depression and anxiety-related disorders are common among adolescents. Research attention to early adolescence and low-income ethnically diverse populations is limited. AIM: To conduct screening for depression and anxiety at an early age with attention to gender and socioenvironmental context within a low-income setting. METHOD: Mixed methods included the PHQ-9A and GAD-10 screening instruments and ethnographic interviews. RESULTS: 75 ethnically diverse middle school students were included. Mean years age was 11.2 (0.74). Females had higher PHQ-9A sum scores than males (p = .002, Mann-Whitney test) and higher GAD-10 sum scores than males (p = .016, Mann-Whitney test). After controlling for multiple comparisons, girls had higher mean responses on three PHQ-9A items (p < .006, two-sided t-test) and only one GAD-10 item (p < .005, two-sided t-test). Ethnographic interviews revealed contexts associated with girls' experiences of depression and anxiety, including gender-based violence in both school and home environments. Salient for girls and boys alike were worries about consequences of COVID-19 for family with respect to illness, death, job loss, economic hardship. Fears over student perceptions of intensified discrimination and racism in school and community were prominent. These problems were experienced by students as barriers to educational engagement. CONCLUSION: Specific attention to early adolescence is needed to identify emergence of subsyndromal conditions which may benefit from therapeutic attention to reduce symptom severity, identify sociocultural, structural, and gender-specific stressors, and to enhance educational engagement.

Investigation of Sulfonium-Iodide-Based Ionic Liquids to Inhibit Corrosion of API 5L X52 Steel in Different Flow Regimes in Acid Medium.

The present work deals with the corrosion inhibition mechanism of API 5L X52 steel in 1 M H2SO4 employing the ionic liquid (IL) decyl(dimethyl)sulfonium iodide [DDMS+I-]. Such a mechanism was elicited by the polarization resistance (R p), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) techniques, both in stationary and dynamic states. The electrochemical results indicated that the corrosion inhibition was controlled by a charge transfer process and that the IL behaved as a mixed-type corrosion inhibitor (CI) with anodic preference. The experimental results revealed maximal inhibition efficiency (IE) rates up to 93% at 150 ppm in the stationary state, whereas in turbulent flow, the IE fell to 65% due to the formation of microvortexes that promoted higher desorption of IL molecules from the surface. The Gibbs free energy of adsorption (ΔG°ads) value of -34.89 kJ mol-1, obtained through the Langmuir isotherm, indicated the formation of an IL monolayer on the metal surface by combining physisorption and chemisorption. The surface analysis techniques confirmed the presence of Fe x O y , FeOOH, and IL on the surface and showed that corrosion damage diminished in the presence of IL. Furthermore, the quantum chemistry calculations (DFT) indicated that the iodide anion hosted most of the highest occupied molecular orbital (HOMO), which eased its adsorption on the anodic sites, preventing the deposition of sulfate ions on the electrode surface.

Inhibition Mechanism of Some Vinylalkylimidazolium-Based Polymeric Ionic Liquids against Acid Corrosion of API 5L X60 Steel: Electrochemical and Surface Studies.

A corrosion inhibition mechanism of API 5L X60 steel exposed to 1.0 M H2SO4 was proposed from the evaluation of three vinylalkylimidazolium poly(ionic liquids) (PILs), employing electrochemical and surface analysis techniques. The synthesized PILs were classified as mixed-type inhibitors whose surface adsorption was promoted mainly by bromide and imidazolate ions, which along with vinylimidazolium cations exerted a resistive effect driven by a charge transfer process by means of a protective PIL film with maximal efficiency of 85% at 175 ppm; the steel surface displayed less surface damage due to the formation of metal-PIL complex compounds.

Ortogonalización de derivaciones de electrocardiograma / Orthogonalization of electrocardiographic derivations

Introducción: El delineador de señales electrocardiográficas (ECG) multiderivación basado en la transformada wavelet posee alta resolución espacial y permite eliminar las diferencias interderivación que aparecen tradicionalmente en los métodos uniderivación. Para esto necesita de derivaciones de señales electrocardiográficas ortogonales entre sí para la obtención de un bucle espacial. Objetivo: Desarrollar métodos de ortogonalización de dos o tres derivaciones de señales electrocardiográficas que permitan la generalización del delineador multiderivación basado en la transformada wavelet en cualquier base de datos señales electrocardiográficas con más de una derivación. Métodos: Se implementaron tres métodos de ortogonalización de derivaciones de señales electrocardiográficas: ortogonalización de dos derivaciones a partir de la proyección de vectores, ortogonalización a partir de componentes principales y ortogonalización a partir del método clásico de Gram-Schmidt. Resultados: Se comparó el funcionamiento del delineador multiderivación de ECG cuando es usado cada método de ortogonalización, mediante el cálculo de la media aritmética y la desviación estándar teniendo en cuenta diferentes combinaciones de derivaciones de ambas bases de datos para cada una de las marcas analizadas. Los mejores resultados se obtuvieron con el método análisis de componentes principales y el peor comportamiento con el método de ortogonalización de dos derivaciones. Conclusiones: Los algoritmos de ortogonalización que obtuvieron los mejores resultados fueron los basados en tres derivaciones ortogonales, en la que fue ligeramente superior la descomposición en componentes principales y, por tanto, se considera el método más adecuado para la generalización del delineador multiderivación(AU)

Introduction: The wavelet transform-based multiderivation electrocardiographic (ECG) signal delineator has high spatial resolution and makes it possible to eliminate interderivation differences traditionally appearing in uniderivation methods. But this requires electrocardiographic signal derivations orthogonal to one another to obtain a spatial loop. Objective: Develop orthogonalization methods of two or three electrographic signal derivations allowing generalization of the wavelet transform-based multiderivation delineator in any electrographic signal database with more than one derivation. Methods: Three orthogonalization methods were implemented for electrocardiographic signal derivations: vector projection-based two-derivation orthogonalization, principal component-based orthogonalization, and orthogonalization based on the Gram-Schmidt classic method. Results: A comparison was performed between the operation of the ECG multiderivation delineator when used with each orthogonalization method. The comparison was based on estimation of the arithmetic mean and standard deviation bearing in mind different combinations of derivations from both databases for each of the marks analyzed. The best results were obtained with the principal component analysis method and the worst ones with the two-derivation orthogonalization method. Conclusions: The orthogonalization algorithms obtaining the best results were those based on three orthogonal derivations, in which decomposition into principal components was slightly higher. This is therefore considered to be the most appropriate method for generalization of the multiderivation delineator(AU)

Loneliness, adolescence, and global mental health: Soledad and structural violence in Mexico.

In this article, we call into question recent public health claims that loneliness is a problem of epidemic proportions. Current research on this topic is hindered by an overreliance on limited survey data and by paradigmatic imbalance that delineates the study of loneliness to psychological, cognitive, neuroendocrinological and immunological effects, social functioning, physical health, mortality, and gene effects. The article emphasizes that scientific approaches to the phenomena of loneliness are more appropriately conceived and investigated as inherently matters for social, relational, cultural, and contextual analysis of subjective experience. Studies of loneliness and possible relationships to mental health status require investigations of social, environmental, and institutional structures as well as families, peers, friends, counselors, and health providers. This article takes a step in this direction through examining the lived experience of 35 high school students and their families living under conditions of social adversity in Tijuana, B.C., Mexico, with attention to anxiety and depression. Utilizing ethnographic interviews, observations, and psychological screening tools, we provide an overview for the group and illustrate the interrelations of subjective experience and social environment through a case study. These data reveal the vital role of understandings of loneliness, depression, and anxiety from the perspectives of adolescents themselves. We conclude that future studies of loneliness are best informed by in-depth data on subjective experience in relation to social features to advance understandings within the field of global mental health and allied fields.

A preliminary RCT of CBT-AD for adherence and depression among HIV-positive Latinos on the U.S.-Mexico border: the Nuevo Día study.

We conducted a preliminary RCT among 40 HIV-positive Latinos of Mexican descent on the U.S.-Mexico border who indicated imperfect adherence and depressive symptomatology. Participants were randomly assigned to culturally adapted cognitive-behavioral therapy for adherence and depression with an alarmed pillbox or usual care. Outcomes were depressive symptoms (self-report and blind clinician ratings), adherence (self-report and electronic pillbox), and biological markers. The intervention, delivered in English and Spanish, proved feasible and acceptable. Generalized estimating equations in intent-to-treat analyses showed some effects of "moderate" to "large" size, with maintenance over time. For example, intervention (vs. control) participants demonstrated at post-intervention a greater drop in BDI scores (OR = -3.64, p = 0.05) and greater adherence according to the electronic pillbox (OR = 3.78, p = 0.03). Biological markers indicated some relative improvement for CD4 count but not VL. The promising results suggest a larger trial to determine efficacy is warranted.

Formation of spherical protein nanoparticles without impacting protein integrity.

Protein formulation at the nanoscale is challenging because of protein susceptibility to chemical and physical degradation during processing. Herein, we present a straightforward method to prepare spherical protein nanoparticles by co-lyophilizing five structurally different enzymes (horseradish peroxidase, carbonic anhydrase, lysozyme, subtilisin Carlsberg and α-chymotrypsin) with methyl-ß-cyclodextrin followed by suspension of the powders in ethyl acetate. The size distribution was narrow and varied from 88 ± 14 to 148 ± 16 nm as determined by dynamic light scattering. Scanning and transmission electron micrographs confirmed the size and spherical morphology of the protein nanoparticles. Residual activities for all enzymes tested were 100% upon dissolving the nanoparticles in buffer and no insoluble aggregates were formed.

Caracterización de la prescripción de antihistamínicos en la consulta externa de un Hospital Nacional / Characterization of the prescription antihistamine in the outpatient unit of a National Hospital

El presente trabajo es un estudio descriptivo cuyo objetivo fue la caracterización de la prescripción de los antihistamínicos en la Consulta Externa en un hospital clase A, nacional, para adultos, de nuestro país; se estudiaron las recetas de antihistamínicos despachadas por el servicio de farmacia durante los meses de enero, febrero y marzo del año 2006. El Servicio de Farmacia del hospital estudiado durante el período despachó a 9260 recetas de antihistamínicos provenientes de la consulta externa. El antihistamínico con mayor prescripción fue el clorhidrato de fexofenadina, la cantidad prescrita superó dos veces la cantidad de hidroxicina, segundo antihistamínico de mayor prescripción. En un 12,75 por ciento del total de las recetas estudiadas se encontró la asociación de fexofenadina con otro antihistamínico de primera generación. El antihistamínico de primera generación que se asoció principalmente con la prescripción de fexofenadina fue hidroxicina, 64,4 por ciento, seguida de clorfeniramina, 30.6 por ciento y difenhidramina, 5.1 por ciento. Se tiene un costo estimado de 9369335.28; de este monto, al menos una cantidad cercana a los 443022.60 fue utilizada en la prescripción de antihistamínicos de primera generación, en forma conjunta con el clorhidrato de fexofenadina...

Truncated forms of human and simian immunodeficiency virus in infected individuals and rhesus macaques are unique or rare quasispecies.

Truncated proviruses of variable sizes are present in peripheral blood mononuclear cells (PBMC) of human immunodeficiency virus type 1 (HIV-1)-infected persons and simian immunodeficiency virus (SIV)-infected rhesus macaques. Here, we investigated whether the highly deleted HIV and SIV proviruses are present in infected organisms as multiple copies or whether each truncated provirus is unique. Using end-point dilution, multiple long-distance (LD) DNA PCR assays were run in parallel using DNA extracted from PBMC of seropositive, treatment-naive persons and from lymph nodes of a rhesus monkey inoculated with cloned, full-length SIVmac239 DNA. The PCR products were titrated and mapped. Most truncated proviruses were present in the DNA samples tested as single, nonintegrated molecules that differed from one another in size and/or nucleotide sequence. These results indicate that truncated primate lentiviral sequences found in infected tissues are unique or rare quasispecies that do not replicate significantly.