Synthesis and characterization of a new octafunctional epoxy resin (Octaglicydil tetra p-aminophenol of bisphenol A (Bis para phosphoric ester)). Viscosimetric study.

In this work, we synthesized a new octafunctional epoxy resin: Octaglicydil tetra p-aminophenol of bisphenol A (Bis para phosphoric ester) (OGTPAPBABPPE). This resin was synthesized in three steps. The first step is intended to condense the phosphorus trichloride and the bisphenol A; the second step was to introduce an aromatic spacer arm between the major epoxide functions and the nucleus of bisphenol A, by reacting p-aminophenol in the precursor dichloride phosphorus bisphenol A; in the third step, we functionalized the latter by the epichlorohydrin.The obtained resin was very viscous and brownish. The latter was characterized by infrared Fourier transform spectroscopy (FTIR), and its chemical structure was also confirmed by proton nuclear magnetic resonance of 1H, 13C atoms and phosphorus 31P (1H NMR, 13C NMR, 31P NMR). The study of viscosi-metric properties was carried out by the viscometer of Ubbelohd type

Predictive ability of problem-solving efficacy sources on mathematics achievement

This study examined the relationship between mathematics achievement and mathematics problem-solving efficacy sources. A cluster sample of 123 first year prospective teachers of a Philippine higher education institution responded to a 30-item problem-solving efficacy scales and took the teacher-made tests in Mathematics in the Modern World course; namely, Non-Routine Problem Solving and Natures and Numbers Pattern Tracing (NRPS-NNPT), Math Language and Symbols (MLS), and Data Management (DM). The research data was analyzed using Descriptive statistics, Pearson-r and Standard Multiple Regression. On the average, the respondents had satisfactory mathematics achievement. They reported a high level of social persuasion and somatic response and a low level of vicarious experience and mastery experience in mathematics problem-solving. Vicarious experience was directly associated with mastery experience while social persuasion and mastery experience were both inversely related to somatic responses. Among the four problem-solving efficacy sources, only social persuasion significantly predicted mathematics achievement specifically in the areas of NRPS-NNPT, MLS, and DM. Thus, becoming a trusted voice of encouragement and designing a persuasive and optimistic learning environment are highly recommended roles of schools to facilitate students’ mathematics achievement

Evaluation of corrosion protection of epoxy coatings on copper during exposure to an aerated 3% NaCl solution.

In this study the anticorrosion performance of a clear epoxy coating was enhanced by the incorporation of modified zinc into the polymer matrix. The structural macroscopy by X-ray diffraction (XRD). Corrosion performance of the coated copper specimens was investigated employing polarization measurements and electrochemical impedance spectroscopy (EIS) in 3% NaCl solution. Incorporation of 5 wt% zinc possessed the best corrosion performance. The electrochemical results are completely in agreement with the morphological results of the surface obtained from scanning electron microscopy (SEM). For the theoretical study, complete geometry optimization of 4, 4′- Ethylene bis (N, N diglycidylaniline) was performed using the Density Functional Theory (DFT). The Gaussian 03W software package was used in the calculations

Scale development and investigation of self-directed learning readiness in Mathematics among Filipino college students

The global shift in higher education brought about by the pandemic has underscored the importance of self-directed learning for academic success, particularly in challenging subjects like mathematics. To assess the self-directed learning readiness in Mathematics among Filipino college students, this study aimed to develop a monitoring instrument that is both structurally valid and reliable. Through an extensive literature review, key indicators relevant to measuring self-directed learning were identified. Subsequently, a 120-item questionnaire was administered to a sample of 326 first-year college students enrolled in Mathematics courses. The data obtained from the questionnaire were subjected to exploratory factor analysis using the Principal Axis Factoring method. This analysis led to the identification of three correlated factors, each consisting of 10 indicators: self-confidence and intelligence, self-monitoring and responsibility, and attitude towards Mathematics learning. These factors collectively explained 56.63% of the observed variation. Furthermore, Pearson correlation analysis revealed direct associations among the identified factors. Notably, students scored significantly lower in the domain of self-confidence and intelligence. The developed instrument demonstrated both simple structure and excellent reliability. These findings provide valuable insights into the self-directed learning readiness of Filipino college students in the context of Mathematics education and lay the foundation for future research and interventions aimed at enhancing self-directed learning practices and promoting academic achievement in this subject area

Stakeholders’ awareness and acceptance of the vision, mission, goals, and outcomes statements of a teacher education college

This study examined the awareness and acceptance of the stakeholders of a teacher education college in the Philippines of their university vision and mission and the college goals, and outcomes statements (VMGOs). Of the 700 target respondents, 406 stakeholders responded to the survey transcribed in Google Form. They were 42 school personnel, 106 parents, and 258 students; 301 females and 105 males. The five-point rating scales asked the respondents to assess their awareness and acceptance of 16 statements including one vision, one mission, five institutional outcomes (IO), two college goals, and seven program outcomes (PO). The respondents as a whole indicated they were very aware of the VMGOs and these were very acceptable for them. However, the school personnel were consistently more aware than the students and the parents/officials; while the parents/officials consistently indicated the lowest awareness and acceptability scores for all the statements. The results further revealed a significant acceptable relationship between awareness and acceptability scores. The variables share a variance ranging from 51% to 61% confirming that as awareness increases, acceptance rate also increases. Various implications of these findings are discussed

Comparative study of inhibitory efficacy of methionine and its derivatives in acidic medium by mild steel

Corrosion inhibition effect of L-Methionine (MT1), L-Methionine sulfoxide (MT2) and L-Methionine sulfone (MT3) on mild steel corrosion in 1M HCl solution was studied by using weight loss, electrochemical polarization and electrochemical impedance spectroscopy (EIS) techniques. The experimental results showed that the inhibitory efficiency of the three aminoacids improves with the increase of concentration to reach the maximum value of 95.20% for MT1, 94.14% for MT2 and 88.92% for MT3 for a concentration of 10-3M, which translates that the surface covered by the inhibitor increases with the concentration. The effect of temperature on the corrosion rate was investigated and some thermodynamic parameters were calculated. Polarization studies show that three studied inhibitors suggested that three inhibitors control the anodic as well as cathodic reactions and act as mixed type in nature. The results show that MT1, MT2 and MT3 are good inhibitors, and the adsorption of each inhibitor on mild steel surface obeys Flory-Huggins and Langmuir, with a better fit of the Langmuir isotherm through mixed adsorption (physisorption as well as chemisorption) process. In addition, the quantum approach based on density functional theory (DFT), monte Carlo (MC) and molecular dynamics (MD) simulations was confirmed the reactivity of the studied compound towards the corrosion process

Toxoplasma gondii IgG Serointensity Is Positively Associated With Frailty

Background: Persistent inflammation related to aging (inflammaging) is exacerbated by chronic infections and contributes to frailty in older adults. We hypothesized associations between Toxoplasma gondii (T. gondii), a common parasite causing an oligosymptomatic unremitting infection, and frailty, and secondarily between T. gondii and previously reported markers of immune activation in frailty.Methods: We analyzed available demographic, social, and clinical data in Spanish and Portuguese older adults [N = 601; age: mean (SD) 77.3 (8.0); 61% women]. Plasma T. gondii immunoglobulin G (IgG) serointensity was measured with an enzyme-linked immunosorbent assay. The Fried criteria were used to define frailty status. Validated translations of Mini-Mental State Examination, Geriatric Depression Scale, and the Charlson Comorbidity Index were used to evaluate confounders. Previously analyzed biomarkers that were significantly associated with frailty in both prior reports and the current study, and also related to T. gondii serointensity, were further accounted for in multivariable logistic models with frailty as outcome.Results: In T. gondii-seropositives, there was a significant positive association between T. gondii IgG serointensity and frailty, accounting for age (p = .0002), and resisting adjustment for multiple successive confounders. Among biomarkers linked with frailty, kynurenine/tryptophan and soluble tumor necrosis factor receptor II were positively associated with T. gondii serointensity in seropositives (p < .05). Associations with other biomarkers were not significant.Conclusions: This first reported association between T. gondii and frailty is limited by a cross-sectional design and warrants replication. While certain biomarkers of inflammaging were associated with both T. gondii IgG serointensity and frailty, they did not fully mediate the T. gondii-frailty association.This work was supported in part by the Spanish Ministry of Science and Innovation: MCIN/AEI/10.13039/501100011033(grant PID2020-113788RB-I00); Xunta de Galicia (grant ED431B 2022/16); Ministry of Education, Culture and Sport (grant BEAGAL18/00142 to V.V.); and Ministry of Economy and Competitiveness, cofinanced by the European Social Fund (grant RYC-2015-18394 to L.L.-L.). Additionally supported, in part, by the University of Maryland School of Medicine Center for Research on Aging in Baltimore, Maryland; a Clinical Science Research & Development Service Merit Award, Office of Research and Development, U.S. Department of Veterans Affairs, Washington, District of Columbia (grant 1 I01 CX001310-01 to T.T.P.); a R01 grant from the National Institute on Aging, National Institutes of Health, Bethesda, Maryland (grant NIA R01 AG018859 to E.J.K.); and by the Military and Veteran Microbiome: Consortium for Research and Education in Aurora, Colorado (L.A.B., A.J.H., C.A.L., T.T.P.). The opinions expressed in the article belong to the authors and cannot be construed as official positions or opinions of the funders, including the U.S. Veterans Affairs Administration and the National Institutes of Health. Data collected and used for the analyses reported in this article are not available because the initial consent did not include this sharing and because other primary analyses have not been completed. Funding for open access charge: Universidade da Coruna/CISUG

Toxoplasma gondii IgG serointensity is positively associated with frailty

[Abstract] Background: Persistent inflammation related to aging ("inflammaging") is exacerbated by chronic infections and contributes to frailty in older adults. We hypothesized associations between Toxoplasma gondii (T. gondii), a common parasite causing an oligosymptomatic unremitting infection, and frailty, and secondarily between T. gondii and previously reported markers of immune activation in frailty. Methods: We analyzed available demographic, social, and clinical data in Spanish and Portuguese older adults [N = 601; age: mean (SD) 77.3 (8.0); 61% women]. Plasma T. gondii immunoglobulin G (IgG) serointensity was measured with an enzyme-linked immunosorbent assay. The Fried criteria were used to define frailty status. Validated translations of Mini-Mental State Examination, Geriatric Depression Scale, and the Charlson Comorbidity Index were used to evaluate confounders. Previously analyzed biomarkers that were significantly associated with frailty in both prior reports and the current study, and also related to T. gondii serointensity, were further accounted for in multivariable logistic models with frailty as outcome. Results: In T. gondii-seropositives, there was a significant positive association between T. gondii IgG serointensity and frailty, accounting for age (p = .0002), and resisting adjustment for multiple successive confounders. Among biomarkers linked with frailty, kynurenine/tryptophan and soluble tumor necrosis factor receptor II were positively associated with T. gondii serointensity in seropositives (p < .05). Associations with other biomarkers were not significant. Conclusions: This first reported association between T. gondii and frailty is limited by a cross-sectional design and warrants replication. While certain biomarkers of inflammaging were associated with both T. gondii IgG serointensity and frailty, they did not fully mediate the T. gondii-frailty association.info:eu-repo/grantAgreement/AEI/Programa Estatal de I+D+i Orientado a los Retos de la Sociedad/PID2020-113788RB-I00/ES/IDENTIFICACION DE FACTORES DE RIESGO Y BIOMARCADORES DE VULNERABILIDAD AL DETERIORO COGNITIVO Y FISICO EN EL ENVEJECIMIENTOXunta de Galicia; ED431B 2022/16Ministerio de Educación, Cultura y Deportes (España); BEAGAL18/0014