Evaluation of Microstructural and Mechanical Behavior of AHSS CP780 Steel Welded by GMAW-Pulsed and GMAW-Pulsed-Brazing Processes

Joints of complex phase 780 (CP-780) advanced high strength steel (AHSS) were carried out by using an ER-CuAl-A2 filler metal for the gas metal arc welding pulsed brazing (GMAW-P- brazing) process and the ER-80S-D2 for the GMAW-P process employing two levels of heat input. The phases in the weld bead and HAZ were analyzed, and the evaporation of zinc by means of scanning electron microscopy (SEM) was also monitored. The mechanical properties of the welded joints were evaluated by tension, microhardness and vertical impact tests. It was found that there was greater surface Zn evaporation in the joints welded with the GMAW-P process as compared to the GMAW-P-brazing process. The best results in tensile strength were observed in the joints welded with GMAW-P-brazing process, which increased by ~68% with respect to those of the GMAW-P. This behavior can be attributed to the formation of an intermetallic complex compound Cu-Al-Fe in the fusion line

Eficiencia energética para empresas que utilizan aire comprimido en su proceso de producción

Eficiencia energética en empresas que utilizan aire comprimido en su proceso de producciónObservación, análisis y propuestas para mejorar la eficiencia energética en las empresas que utilizan aire comprimido para sus procesos

Cost-Effective Thermal-Insulating Building Materials

We report on the development of a formula for an adequate mix of aggregates to produce concrete blocks, which, while preserving high mechanical resistance, show good thermal insulation and reduced production costs. Three aggregates with different proportions were compared, consisting of pumice, wood shavings and basalt; the amounts of each material were 1800, 1970 and 2150 kg. A three-factor experimental design was applied to statistically determine the best factors for the response variables, namely, a high compression resistance and low thermal conductivity. The best mix obtained is composed of 250 kg of cement, 1970 kg of pumice and three amounts of sand with minor differences

The folic acid metabolite 7,8-dihydrofolate can decrease the interactions of ACE2 with the Wild type, but not with the Beta and Delta SARS-CoV-2 variants: A silico study.

There is evidence that high levels of folic acid in human plasma may prevent SARS-CoV-2 infections or reduce its symptoms. However, the mechanisms that enable this inhibition are still unknown. This article proves, through molecular dynamics simulation, that folic acid metabolite 7,8-dihydrofolate (DHF) has high affinity to bind as ligands to the angiotensin-converting enzyme 2 (ACE2), and when this complex has been formed, the Wild type SARS-CoV-2 virus cannot bind to the ACE2 receptor, possibly inhibiting infection to the host cell. In contrast, the Beta and Delta variants of this same virus can join the ACE2 with high affinity even with the presence of DHF. This results lead to the conclusion that DHF may inhibit infection from the Wild type SARS-CoV-2 virus, but not its Beta and Delta variants. These results could explain the almost double increase in severe cases of COVID-19 due to the delta variant in pregnant women compared to the Wild type SARS-CoV-2

Clinical Characteristics of Coronavirus Disease (COVID-19) in Mexican Children and Adolescents

Background: We analyzed the demographic, clinical, and diagnostic data of children and adolescents in Mexico, from the first case of coronavirus disease (COVID-19) to 28 February 2022. Methods: Using the open databases of the Ministry of Health and a tertiary pediatric hospital, we obtained demographic and clinical data from the beginning of the COVID-19 pandemic until 28 February 2022. In addition, quantitative reverse-transcription polymerase chain reaction outputs were used to determine the viral load, and structural protein-based serology was performed to evaluate IgG antibody levels. Results: Of the total 437,832 children and adolescents with COVID-19, 1187 died. Of these patients, 1349 were admitted to the Hospital Infantil de Mexico Federico Gómez, and 11 died. Obesity, asthma, and immunosuppression were the main comorbidities, and fever, cough, and headache were the main symptoms. In this population, many patients have a low viral load and IgG antibody levels. Conclusion: During the first 2 years of the COVID-19 pandemic in Mexico, children and adolescents had low incidence and mortality. They are a heterogeneous population, but many patients had comorbidities such as obesity, asthma, and immunosuppression; symptoms such as fever, cough, and headache; and low viral load and IgG antibodies

Increased α-tocopherol metabolism in horses with equine neuroaxonal dystrophy.

BackgroundEquine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is an inherited neurodegenerative disorder associated with a vitamin E deficiency within the first year of life. Vitamin E consists of 8 isoforms metabolized by the CYP4F2 enzyme. No antemortem diagnostic test currently exists for eNAD/EDM.Hypothesis/objectivesBased on the association of α-tocopherol deficiency with the development of eNAD/EDM, we hypothesized that the rate of α-tocopherol, but not γ-tocopherol or tocotrienol metabolism, would be increased in eNAD/EDM-affected horses.AnimalsVitamin E metabolism: Proof of concept (POC) study; eNAD/EDM-affected (n = 5) and control (n = 6) horses. Validation study: eNAD/EDM-affected Quarter Horses (QHs; n = 6), cervical vertebral compressive myelopathy affected (n = 6) horses and control (n = 29) horses. CYP4F2 expression and copy number: eNAD/EDM-affected (n = 12) and age- and sex-matched control (n = 11-12) horses.MethodsThe rates of α-tocopherol/tocotrienol and γ-tocopherol/tocotrienol metabolism were assessed in equine serum (POC and validation) and urine (POC only) using liquid chromatography tandem mass spectrometry (LC-MS/MS). Quantitative reverse-transcriptase PCR (qRT-PCR) and droplet digital (dd)-PCR were used to assay expression and genomic copy number of a CYP4F2 equine ortholog.ResultsMetabolic rate of α-tocopherol was increased in eNAD/EDM horses (POC,P < .0001; validation, P = .03), with no difference in the metabolic rate of γ-tocopherol. Horses with eNAD/EDM had increased expression of the CYP4F2 equine orthologue (P = .02) but no differences in copy number.Conclusions and clinical importanceIncreased α-tocopherol metabolism in eNAD/EDM-affected QHs provides novel insight into alterations in vitamin E processing in eNAD/EDM and highlights the need for high-dose supplementation to prevent the clinical phenotype in genetically susceptible horses