Electron bifurcation mechanism and homoacetogenesis explain products yields in mixed culture anaerobic fermentations

Anaerobic fermentation of organic wastes using microbial mixed cultures is a promising avenue to treat residues and obtain added-value products. However, the process has some important limitations that prevented so far any industrial application. One of the main issues is that we are not able to predict reliably the product spectrum (i.e. the stoichiometry of the process) because the complex microbial community behaviour is not completely understood. To address this issue, in this work we propose a new metabolic network of glucose fermentation by microbial mixed cultures that incorporates electron bifurcation and homoacetogenesis. Our methodology uses NADH balances to analyse published experimental data and evaluate the new stoichiometry proposed. Our results prove for the first time the inclusion of electron bifurcation in the metabolic network as a better description of the experimental results. Homoacetogenesis has been used to explain the discrepancies between observed and theoretically predicted yields of gaseous H2 and CO2 and it appears as the best solution among other options studied. Overall, this work supports the consideration of electron bifurcation as an important biochemical mechanism in microbial mixed cultures fermentations and underlines the importance of considering homoacetogenesis when analysing anaerobic fermentations

La competencia digital del alumnado de Educación Primaria desde la perspectiva de género: conocimientos, actitudes y prácticas

This article seeks to investigate from a gender perspective the synergies and divergences between the digital knowledge, skills, attitudes and practices of girls and boys in 6th grade of Primary School. To this end, the study design is an exploratory sequential mixed method divided into two phases: an initial multiple case study from an ethnographic perspective, followed by a phase in which a sample of 588 schoolchildren in Galicia took the ECODIES digital competence assessment test. The results reveal substantial gender differences and that the mother's socio-cultural capital is fundamental to the acquisition of digital competence for the student.Este artículo busca indagar en las sinergias y divergencias entre conocimientos, habilidades, actitudes y prácticas digitales del alumnado de 6º de Primaria desde una perspectiva de género. Para ello, se propone un diseño mixto secuencial exploratorio en dos fases: un estudio de casos múltiple con perspectiva etnográfi ca; y la aplicación de la prueba de evaluación de la competencia digital ECODIES a una muestra de 588 escolares de Galicia. Los resultados advierten diferencias sustanciales en función del género; y señalan el capital sociocultural materno como elemento fundamental para la adquisición de la competencia digital

Accuracy of periodontitis diagnosis obtained using multiple molecular biomarkers in oral fluids: A systematic review and meta‐analysis

Aim To determine the accuracy of biomarker combinations in gingival crevicular fluid (GCF) and saliva through meta-analysis to diagnose periodontitis in systemically healthy subjects. Methods Studies on combining two or more biomarkers providing a binary classification table, sensitivity/specificity values or group sizes in subjects diagnosed with periodontitis were included. The search was performed in August 2022 through PUBMED, EMBASE, Cochrane, LILACS, SCOPUS and Web of Science. The methodological quality of the articles selected was evaluated using the QUADAS-2 checklist. Hierarchical summary receiver operating characteristic modelling was employed to perform the meta-analyses (CRD42020175021). Results Twenty-one combinations in GCF and 47 in saliva were evaluated. Meta-analyses were possible for six salivary combinations (median sensitivity/specificity values): IL-6 with MMP-8 (86.2%/80.5%); IL-1β with IL-6 (83.0%/83.7%); IL-1β with MMP-8 (82.7%/80.8%); MIP-1α with MMP-8 (71.0%/75.6%); IL-1β, IL-6 and MMP-8 (81.8%/84.3%); and IL-1β, IL-6, MIP-1α and MMP-8 (76.6%/79.7%). Conclusions Two-biomarker combinations in oral fluids show high diagnostic accuracy for periodontitis, which is not substantially improved by incorporating more biomarkers. In saliva, the dual combinations of IL-1β, IL-6 and MMP-8 have an excellent ability to detect periodontitis and a good capacity to detect non-periodontitis. Because of the limited number of biomarker combinations evaluated, further research is required to corroborate these observationsThis study was funded by the Instituto de Salud Carlos III (ISCIII) through the project PI21/00588 and co-funded by the European UnionS

Role of the extended lymphadenectomy in gastric cancer surgery: experience

Although curative resection is the treatment of choice for gastric cancer, controversy exists about the adequate extent of lymph node dissection when resection is performed. METHODS: We retrospectively assessed 85 patients who underwent a limited lymphadenectomy (D1) and 71 who had an extended lymph node dissection (D2) in a single institution between 1990 and 1998 (median follow-up, 37.3 months). Prognostic factors were assessed by Cox proportional hazard models adjusted for potential confounders. RESULTS: We found no significant difference in the length of hospital stay (median, 12.1 and 13.1 days), overall morbidity (48.2% and 53.5%), or operative mortality (2.3% and 0%) between D1 and D2, respectively. Five-year survival in the D2 group was longer (50.6%) than in the D1 group (41.4%) for tumor stages (tumor-node-metastasis) >I. In multivariate analysis, tumor-node-metastasis stage (hazard ratio for stages >I vs. 0-I, 11.6), the ratio between invaded and removed lymph nodes, the presence of distant metastases, Lauren classification, and the extent of lymphadenectomy (hazard ratio for D1 vs. D2, 2.3; 95% confidence interval, 1.25-4.30) were the only significant prognostic factors. CONCLUSIONS: Our experience shows that extended (D2) lymph node dissection improves survival in patients with resected gastric cancer

Volumetric behaviour of six ionic liquids from T = (278 to 398) K and up to 120 MPa

© 2015 Elsevier Ltd. All rights reserved. In this paper the volumetric behaviour of the ionic liquids 1-butyl-1-methylpyrrolidinium tetracyanoborate, 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, 1,3-dimethylimidazolium dimethylphosphate, 1-ethyl-3-methylimidazolium hexylsulfate, and trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate is reported. Density was measured over the temperature range (278.15 to 398.15) K up to 120 MPa by means of a high pressure densimeter based on the vibrating tube principle. Experimental values were correlated as a function of temperature and pressure by means of the Tammann-Tait equation obtaining standard deviations lower than 3 × 10-4 g · cm-3. From this correlation, isothermal compressibility and isobaric thermal expansivity are obtained by differentiation. Furthermore, two group contribution methods proposed by Gardas and Coutinho and by Jacquemin et al. are applied to these fluids to analyse their prediction abilities to determine densities, as well as an equation proposed by Kiselev et al. to obtain isothermal compressibility at 0.1 MPa