Design, Validation, and Fabrication of a Tailored Electrochemical Reactor Using 3D Printing for Studies of Commercial Boron-Doped Diamond Electrodes.

Boron-doped diamond (BDD) electrodes are the most effective and resistant electrodic materials to perform advanced oxidation processes. Having a reactor that can provide adequate hydrodynamic conditions is mandatory to use these electrodes effectively. In this work, the diamond anode electrochemical reactor (E3L-DAER) is designed to fulfill this necessity. Several features are included to improve its efficiency, like conic inlet/outlet, flow enhancers, and a reduced interelectrode gap. The fluid dynamic validation has been performed using computer fluid dynamics (CFD) calculations, residence time distribution (RDT) curves, and mass transfer analysis. The reactor has been made using a three-dimensional (3D) printing stereolithography (SLA) technique, which allows us to build chemical-resistant reactors with nonstandard and tailored features in a cheap and fast way. The obtained results demonstrate that the designed reactor has the required fluid dynamics properties to perform reliable BDD electrode studies and applications. Finally, a BDD electrode was used to test the production of different oxidants such as persulfate, peroxophosphate, and chlorine-derived species.

Efficacy of ozone injections for reducing musculoskeletal pain in comparison with corticosteroid injections: A systematic review and meta-analysis.

BACKGROUND: Corticosteroid injections are frequently used in the short-term treatment of musculoskeletal pain, but their use is controversial as repeated exposures to corticosteroids can lead to deleterious effects on musculoskeletal tissue. Ozone injections have been proposed as a possible treatment for musculoskeletal pain; however, their effectiveness has not been compared with corticosteroids. OBJECTIVE: To evaluate the effectiveness of ozone injections for reducing pain in individuals with musculoskeletal pain in comparison with corticosteroid injections through a meta-analysis. METHODS: An online systematic search was performed using electronic databases up to September 2023. We searched for studies that compared corticosteroid injections with ozone injections in the treatment of musculoskeletal pain of diverse origins. RESULTS: Eleven studies were included comprising a total of 534 individuals. In the overall pooled analysis, a pain reduction in favor of corticosteroid injections was found in the short term (d= 0.31, 95% CI 0.01 to 0.60, p (z) 0.04, I2 = 32%). In the medium term, no significant differences were found in reducing pain between groups (d=-0.17, 95% CI -0.42 to 0.07, p (z) 0.15, I2 = 0%). CONCLUSIONS: Our results suggest that corticosteroids injections are more effective in reducing musculoskeletal pain in the short term, but equally effective in the medium term when compared with ozone injections. Nonetheless, better-quality clinical trials are necessary to corroborate these results.

Evolutionary Dynamics of Mexican Lineage H5N2 Avian Influenza Viruses.

We have demonstrated for the first time a comprehensive evolutionary analysis of the Mexican lineage H5N2 avian influenza virus (AIV) using complete genome sequences (n = 189), from its first isolation in 1993 until 2019. Our study showed that the Mexican lineage H5N2 AIV originated from the North American wild bird gene pool viruses around 1990 and is currently circulating in poultry populations of Mexico, the Dominican Republic, and Taiwan. Since the implementation of vaccination in 1995, the highly pathogenic AIV (HPAIV) H5N2 virus was eradicated from Mexican poultry in mid-1995. However, the low pathogenic AIV (LPAIV) H5N2 virus has continued to circulate in domestic poultry populations in Mexico, eventually evolving into five distinct clades. In the current study, we demonstrate that the evolution of Mexican lineage H5N2 AIVs involves gene reassortments and mutations gained over time. The current circulating Mexican lineage H5N2 AIVs are classified as LPAIV based on the amino acid sequences of the hemagglutinin (HA) protein cleavage site motif as well as the results of the intravenous pathogenicity index (IVPI). The immune pressure from vaccinations most likely has played a significant role in the positive selection of antigenic drift mutants within the Mexican H5N2 AIVs. Most of the identified substitutions in these viruses are located on the critical antigenic residues of the HA protein and as a result, might have contributed to vaccine failures. This study highlights and stresses the need for vaccine updates while emphasizing the importance of continued molecular monitoring of the HA protein for its antigenic changes compared to the vaccines used.

Retrieval of germinal zone neural stem cells from the cerebrospinal fluid of premature infants with intraventricular hemorrhage.

Intraventricular hemorrhage is a common cause of morbidity and mortality in premature infants. The rupture of the germinal zone into the ventricles entails loss of neural stem cells and disturbs the normal cytoarchitecture of the region, compromising late neurogliogenesis. Here we demonstrate that neural stem cells can be easily and robustly isolated from the hemorrhagic cerebrospinal fluid obtained during therapeutic neuroendoscopic lavage in preterm infants with severe intraventricular hemorrhage. Our analyses demonstrate that these neural stem cells, although similar to human fetal cell lines, display distinctive hallmarks related to their regional and developmental origin in the germinal zone of the ventral forebrain, the ganglionic eminences that give rise to interneurons and oligodendrocytes. These cells can be expanded, cryopreserved, and differentiated in vitro and in vivo in the brain of nude mice and show no sign of tumoral transformation 6 months after transplantation. This novel class of neural stem cells poses no ethical concerns, as the fluid is usually discarded, and could be useful for the development of an autologous therapy for preterm infants, aiming to restore late neurogliogenesis and attenuate neurocognitive deficits. Furthermore, these cells represent a valuable tool for the study of the final stages of human brain development and germinal zone biology.

Electrocatalytic studies on imidazolium based ionic liquids: defining experimental conditions.

The number of publications devoted to studying electrochemical reactions in room temperature ionic liquids (RTILs) is constantly growing, but very few of them have been devoted to defining proper experimental conditions to obtain reproducible electrochemical results. In this work, we demonstrate that the combination of a proper RTIL purification treatment and a filtered Ar gas stream allow us to obtain featureless voltammograms in [C4mim][BF4], [C4mim][NTf2], and [C4m2im][NTf2], which otherwise present signals associated with different types of impurities such as water and some minor electroactive impurities acquired during the RTIL synthesis process. Moreover, we demonstrate that bubbling Ar, or another inert gas, through the electrolyte in order to purge O2 dissolved in RTILs is one of the major sources of water and O2 impurities incorporated in RTILs within the electrochemical cell. To overcome this source of water uptake, we have incorporated a gas stream purification filter before the gas reaches the RTIL in the electrochemical cell. To illustrate the effect of these impurities in relevant electrocatalytic studies, we study the electrocatalytic reduction of CO2 on Pt nanoparticles and the key role of an appropiate filter when the CO2 gas stream is bubbled within imidazolium based RTILs. Our cyclic voltammetric studies point out that CO2 electroreduction on Pt nanoparticles only presents activity in [C4mim][NTf2] and [C4m2im][NTf2], thus suggesting that the C-2 position on the imidazolium ring is not the key position in CO2 electrochemical reduction. In contrast, the same Pt nanoparticles are inactive towards CO2 electroreduction in [C4mim][BF4], which is a more hydrophilic RTIL.

Surface structured platinum electrodes for the electrochemical reduction of carbon dioxide in imidazolium based ionic liquids.

The direct CO2 electrochemical reduction on model platinum single crystal electrodes Pt(hkl) is studied in [C2mim(+)][NTf2(-)], a suitable room temperature ionic liquid (RTIL) medium due to its moderate viscosity, high CO2 solubility and conductivity. Single crystal electrodes represent the most convenient type of surface structured electrodes for studying the impact of RTIL ion adsorption on relevant electrocatalytic reactions, such as surface sensitive electrochemical CO2 reduction. We propose here based on cyclic voltammetry and in situ electrolysis measurements, for the first time, the formation of a stable adduct [C2mimH-CO2(-)] by a radical-radical coupling after the simultaneous reduction of CO2 and [C2mim(+)]. It means between the CO2 radical anion and the radical formed from the reduction of the cation [C2mim(+)] before forming the corresponding electrogenerated carbene. This is confirmed by the voltammetric study of a model imidazolium-2-carboxylate compound formed following the carbene pathway. The formation of that stable adduct [C2mimH-CO2(-)] blocks CO2 reduction after a single electron transfer and inhibits CO2 and imidazolium dimerization reactions. However, the electrochemical reduction of CO2 under those conditions provokes the electrochemical cathodic degradation of the imidazolium based RTIL. This important limitation in CO2 recycling by direct electrochemical reduction is overcome by adding a strong acid, [H(+)][NTf2(-)], into solution. Then, protons become preferentially adsorbed on the electrode surface by displacing the imidazolium cations and inhibiting their electrochemical reduction. This fact allows the surface sensitive electro-synthesis of HCOOH from CO2 reduction in [C2mim(+)][NTf2(-)], with Pt(110) being the most active electrode studied.

Mexican American mothers of low and middle socioeconomic status: communication behaviors and interactive strategies during shared book reading.

PURPOSE: The aim of this investigation was to describe and compare the communication behaviors and interactive reading strategies used by Mexican American mothers of low- and middle-socioeconomic status (SES) background during shared book reading. METHOD: Twenty Mexican American mother-child dyads from the Southwestern United States were observed during two book reading sessions. The data were coded across a number of communication behavior categories and were analyzed using the Adult/Child Interactive Reading Inventory (ACIRI; A. DeBruin-Parecki, 1999). RESULTS: Mexican American mothers used a variety of communication behaviors during shared book reading with their preschool children. Significant differences between the SES groups regarding the frequency of specific communication behaviors were revealed. Middle-SES mothers used positive feedback and yes/no questions more often than did low-SES mothers. Mexican American mothers also used a variety of interactive reading strategies with varying frequency, as measured by the ACIRI. They enhanced attention to text some of the time, but rarely promoted interactive reading/supported comprehension or used literacy strategies. There were no significant differences between the SES groups regarding the frequency of interactive reading strategies. CONCLUSION: Parent literacy programs should supplement Mexican American mothers' communication behaviors and interactive reading strategies to improve effectiveness and participation.