The University of Zulia (Spanish: La Universidad del Zulia, also known as LUZ literally meaning "light" in Spanish), is a public university whose main campus is located in the city of Maracaibo, Venezuela. LUZ is one of the largest and most important universities of Venezuela.The University of Zulia has three campuses: two in Zulia State, in the cities of Maracaibo (being the biggest and most important of the three) and Cabimas; and one in the city of Punto Fijo, located in Falcón State..
The hydroformylation of alkenylbenzenes remains insufficiently defined, despite the relevance of these substrates as biomass-derived aromatic feedstocks within sustainable chemical transformations. In this work, we present an experimental (catalytic and kinetic) study of their conversion into aldehydes under rhodium-phosphine catalysis, using complexes bearing mono-, bi- and tridentate phosphine ligands, [Rh(H)(CO)(2)(PPh3)(2)], [Rh(H)(CO)(triphos)] and [Rh(H)(CO)(2)(dppe)], under mild reaction conditions (80 degrees C and 2-30 bar of syngas for eugenol; 80 degrees C and 20-50 bar of syngas for estragole and trans-anethole). The catalytic activity order of the complexes was Rh (PPh3) > Rh(triphos) > Rh(dppe), while the substrate reactivity followed the trend eugenol > estragole >> trans-anethole. Reaction rates were measured across a wide CO and H-2 pressure range, revealing redistribution between the active monocarbonyl species and an off-cycle (acyl)dicarbonyl complex that becomes dominant at elevated p(CO). The kinetic behavior observed for eugenol hydroformylation with Rh(PPh3) was consistent with the established hydroformylation sequence involving alkene coordination, hydride migration to substrate and the CO-dependent re-coordination steps that determine catalyst speciation; the subsequent transfer of the alkyl group to the carbonyl ligand and hydrogenolysis complete the catalytic cycle; the H-2 addition or the hydride transfer to the alkene was identified as the rate-determining step, depending on whether low or high p(H-2) values were employed. To obtain statistically reliable kinetic parameters- often challenging in hydroformylation because of parameter covariance and restricted identifiability- we complemented conventional nonlinear regression with Bayesian inference based on the Markov Chain Monte Carlo approach. The resulting posterior distributions were well centered, exhibited realistic variance and provided parameter sets that are sufficiently robust to support mechanistic interpretation and subsequent kinetic modeling.
Opuntia cochenillifera (L.) Mill. has a forage potential in arid areas. Because pastures are insufficient to meet livestock's nutritional demands during the dry season, this research aimed to evaluate the effects of sectioning (S), drying (D), and shading (Sh) of cladodes on the propagation of Opuntia cochenillifera (L.) Mill. The S factors (whole cladode and apical, middle, and basal sections), D (pre-drying at room temperature on mesh under shade for 14 days), and Sh (with and without shading under 80 % density raffia mesh), resulted in a combination of 16 treatments, arranged in a split-plot treatment design and a completely randomized experimental design. Percentages of living, rooted, and sprouted cladodes, number of shoots per cladode, and number and length of roots were evaluated 35 days after establishment. An analysis of variance and a means test were applied to determine differences among treatments. An increase in the percentage of rooted cladodes was obtained with the middle, apical, and basal fractions compared to the whole cladode, regardless of the drying process. Prior shading was counterproductive for cladode survival; high environmental humidity, combined with their water content, may have favored the appearance of secondary rots. In general, considering most of the variables evaluated, cladode sectioning without drying emerged as the best technique for asexual propagation of the species, due to the yield of vegetative material and its practicality.
Population aging has transformed oral health into a major public health concern worldwide. Older adults commonly experience tooth loss, periodontal disease, xerostomia, polypharmacy-induced salivary dysfunction and reduced masticatory efficiency conditions that negatively affect nutrition, cognition, communication and overall quality of life. Growing evidence supports bidirectional relationships between oral diseases and systemic disorders including cardiovascular disease, diabetes mellitus, aspiration pneumonia and cognitive decline, all of which increase the complexity of rehabilitation in aging populations. This review analyzes recent evidence on the impact of aging on oral health, examining oral-systemic interactions, polypharmacy effects, functional decline related to mastication and challenges of prosthetic rehabilitation in older adults. The literature demonstrates that masticatory efficiency extends well beyond food breakdown, functioning as a clinical indicator of broader functional vulnerability. Integrating oral health into geriatric care pathways is essential for improving health outcomes in an aging world.
Ischemic cardiomyopathy remains a leading cause of cardiovascular mortality. Although autologous CD133⁺ progenitor cell therapy has been investigated as an adjunct to coronary artery bypass grafting (CABG), its clinical efficacy and safety remain uncertain. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of autologous CD133⁺ cell therapy administered during CABG in patients with ischemic cardiomyopathy. A comprehensive search of PubMed/MEDLINE, Embase, Web of Science, Scopus, Google Scholar, and the Cochrane Library was conducted from database inception to January 2026. Eligible studies included randomized controlled trials and observational studies involving adults with ischemic cardiomyopathy in whom intraoperative administration of autologous CD133⁺ cells during CABG was compared with CABG alone. Random-effects meta-analyses were performed using maximum likelihood estimation with Hartung-Knapp adjustment. The certainty of evidence for critical and important outcomes was assessed using GRADE. Eleven studies encompassing 495 participants were included (7 RCTs, 4 cohort studies). No significant between-group difference was observed in MRI-assessed LVEF (MD − 1.34
Cultural ecosystem services (CES) value the intangible benefits that ecosystems provide to people and are useful tools for urban planning and management. This study aims to identify CES in urban areas peripheral to the El Tablazo Petrochemical Complex, Venezuela. Based on the review of urban plans, questionnaires to experts and participatory mapping with focus groups, the main ecosystems and their benefits are identified. The marshes and the Altagracia coast (Lake Maracaibo) stand out as key ecosystems, together with the system of green public spaces (streets, squares, waterfront promenade), providing recreational, physical and emotional benefits. These spaces, despite the tension with petrochemical activity, are essential for the articulation of the city, contributing to the quality of life and well-being of its inhabitants.
