Dry purification of ethanolic biodiesel produced from waste cooking oils through adsorption processes

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáDue to the risk of possible depletion of fossil fuels and the increasing consumption of energy from renewable energy sources, biodiesel emerges as an alternative to non-renewable fuel. An important stage in its production process is purification, commonly done through wet washing to remove glycerol in solution. However, this method consumes large volumes of water, resulting in significant effluent volumes. Therefore, this study aimed to apply adsorption as an alternative method. To apply this method, the chosen agroindustrial waste was olive pit, as it is widely produced in Portugal and was implemented in the form of activated carbon. The overall process involved three main stages: biodiesel and activated carbon production, subsequent characterization, and adsorption tests for glycerol removal. Biodiesel was produced through transesterification of waste cooking oil under specific conditions, resulting in a sample with high glycerol content, incomplete conversion to fatty acid esters, and high in linoleic acid ethyl ester, indicating the presence of sunflower oil. The activated carbon was produced from dry olive pits and showed basic characteristics, suitable for glycerol removal. Adsorption kinetic tests revealed that the activated carbon was favorable in removing glycerol from the biodiesel, with the best result achieved at 25°C after 1440 minutes, reaching 89.7% glycerol removal. The isotherm models used in the study showed favorable results, indicating that adsorption occurred in a multilayer formation and on a heterogeneous surface. However, the study concluded that while the activated carbon contributes to biodiesel purification, it cannot completely substitute wet washing due to the inability to achieve the required glycerol content limit in a single stage process. In the future, other conditions may be added to this work, for example: use different kinds of WCO, different activations of the adsorbent, different transesterification conditions, recycle AC, and change the purification from batch to continuous process. The study's results provide valuable insights into the potential of olive pits activated carbon for biodiesel purification and the limitations of its use as a complete substitute for wet washingDevido ao risco de possível esgotamento de combustíveis fósseis e ao aumento de consumo de energia de energias de fontes renováveis, o biodiesel surge como uma alternativa para os combustíveis de fontes não-renováveis. Uma importante etapa para o seu processo de produção é a purificação, comumente feita por lavagens aquosas, a fim de remover o glicerol em solução. Entretanto, esse método consume grandes volumes de água, gerando assim grandes volumes de efluente. Dessa forma, este estudo teve como objetivo aplicar a adsorção como método alternativo. Para aplicar este método, o resíduo agroindustrial escolhido foi o caroço de azeitona, uma vez que é amplamente produzido em Portugal e foi implementado na forma de carbono ativado. O processo global envolveu três etapas principais: produção de biodiesel e de carvão ativado, posterior caracterização e testes de adsorção para remoção do glicerol. O biodiesel foi produzido por transesterificação de óleo residual alimentar, resultando em uma amostra com alto teor de glicerol, conversão incompleta em ésteres de ácidos graxos e alto teor de ésteres etílicos de ácido linoleico, indicando a predominância de óleo de girassol. O carbono ativado foi produzido a partir de caroços secos de azeitona e apresentou características básicas, adequadas para a remoção de glicerol. Testes cinéticos de adsorção revelaram que o carbono ativado foi favorável na remoção de glicerol do biodiesel, com o melhor resultado alcançado, 89.7 % de remoção, a 25 °C após 24 h. Os modelos de isotérmicas de Freundlich, Langmuir e BET usados no estudo mostraram resultados favoráveis, indicando que a adsorção ocorreu em multicamada e em uma superfície heterogênea. No entanto, o estudo permitiu concluir que, embora o adsorvente preparado contribua para a purificação do biodiesel, ele não pode substituir completamente a lavagem húmida devido à incapacidade de atingir o limite de teor de glicerol requerido com um processo de passo único. No futuro, outras condições podem ser adicionadas, como por exemplo: usar diferentes tipos de óleo residual de cozinha, diferentes ativações do adsorvente, diferentes condições de transesterificação, reciclar o carbono ativado e mudar o processo de batelada para contínuo. Os resultados do estudo fornecem informações valiosas sobre o potencial do carvão ativado do caroço de azeitona para a purificação do biodiesel e as limitações de seu uso como substituto completo para a lavagem húmida

Endothelial Wnt/β-catenin signaling inhibits glioma angiogenesis and normalizes tumor blood vessels by inducing PDGF-B expression

Endothelial Wnt/β-catenin signaling is necessary for angiogenesis of the central nervous system and blood–brain barrier (BBB) differentiation, but its relevance for glioma vascularization is unknown. In this study, we show that doxycycline-dependent Wnt1 expression in subcutaneous and intracranial mouse glioma models induced endothelial Wnt/β-catenin signaling and led to diminished tumor growth, reduced vascular density, and normalized vessels with increased mural cell attachment. These findings were corroborated in GL261 glioma cells intracranially transplanted in mice expressing dominant-active β-catenin specifically in the endothelium. Enforced endothelial β-catenin signaling restored BBB characteristics, whereas inhibition by Dkk1 (Dickkopf-1) had opposing effects. By overactivating the Wnt pathway, we induced the Wnt/β-catenin–Dll4/Notch signaling cascade in tumor endothelia, blocking an angiogenic and favoring a quiescent vascular phenotype, indicated by induction of stalk cell genes. We show that β-catenin transcriptional activity directly regulated endothelial expression of platelet-derived growth factor B (PDGF-B), leading to mural cell recruitment thereby contributing to vascular quiescence and barrier function. We propose that reinforced Wnt/β-catenin signaling leads to inhibition of angiogenesis with normalized and less permeable vessels, which might prove to be a valuable therapeutic target for antiangiogenic and edema glioma therapy

Los mártires de la UCA y la Compañía de Jesús en los Estados Unidos

No abstract available. ECA Estudios Centroamericanos, Vol. 69, No. 739, 2014: 415-419.No hay resúmenes disponibles. ECA Estudios Centroamericanos, Vol. 69, No. 739, 2014: 415-419

Hypothalamic Wnt signalling and its role in energy balance regulation

yesWnt signalling and its downstream effectors are well known for their roles in embryogenesis and tumourigenesis, including the regulation of cell proliferation, survival and differentiation. In the nervous system, Wnt signalling has been described mainly during embryonic development, although accumulating evidence suggests that it also plays a major role in adult brain morphogenesis and function. Studies have predominantly concentrated on memory formation in the hippocampus, although recent data indicate that Wnt signalling is also critical for neuroendocrine control of the developed hypothalamus, a brain centre that is key in energy balance regulation and whose dysfunction is implicated in metabolic disorders such as type 2 diabetes and obesity. Based on scattered findings that report the presence of Wnt molecules in the tanycytes and ependymal cells lining the third ventricle and arcuate nucleus neurones of the hypothalamus, their potential importance in key regions of food intake and body weight regulation has been investigated in recent studies. The present review brings together current knowledge on Wnt signalling in the hypothalamus of adult animals and discusses the evidence suggesting a key role for members of the Wnt signalling family in glucose and energy balance regulation in the hypothalamus in diet-induced and genetically obese (leptin deficient) mice. Aspects of Wnt signalling in seasonal (photoperiod sensitive) rodents are also highlighted, given the recent evidence indicating that the Wnt pathway in the hypothalamus is not only regulated by diet and leptin, but also by photoperiod in seasonal animals, which is connected to natural adaptive changes in food intake and body weight. Thus, Wnt signalling appears to be critical as a modulator for normal functioning of the physiological state in the healthy adult brain, and is also crucial for normal glucose and energy homeostasis where its dysregulation can lead to a range of metabolic disorders

The ecological efficiency assessment in the system of management

The article presents models and methods of environmental efficiency assessment. The analysis of methodological approaches to environmental efficiency assessment has been carried out. The research concludes that the indicators of ecological management benefit and costs and nature protection activity are key criteria in environmental efficiency estimation

Ross-Konno and Endocardial Fibroelastosis Resection After Hybrid Stage I Palliation in Infancy: Successful Staged Left-Ventricular Rehabilitation and Conversion to Biventricular Circulation After Fetal Diagnosis of Aortic Stenosis

We report a patient who presented during fetal life with severe aortic stenosis, left-ventricular dysfunction, and endocardial fibroelastosis (evolving hypoplastic left heart syndrome). Management involved in utero and postnatal balloon aortic valvuloplasty for partial relief of obstruction and early postnatal hybrid stage I palliation until recovery of left-ventricular systolic function had occurred. The infant subsequently had successful conversion to a biventricular circulation by combining resection of endocardial fibroelastosis with single-stage Ross-Konno, aortic arch reconstruction, hybrid takedown, and pulmonary artery reconstruction

Expression profiling of blood samples from an SU5416 Phase III metastatic colorectal cancer clinical trial: a novel strategy for biomarker identification

BACKGROUND: Microarray-based gene expression profiling is a powerful approach for the identification of molecular biomarkers of disease, particularly in human cancers. Utility of this approach to measure responses to therapy is less well established, in part due to challenges in obtaining serial biopsies. Identification of suitable surrogate tissues will help minimize limitations imposed by those challenges. This study describes an approach used to identify gene expression changes that might serve as surrogate biomarkers of drug activity. METHODS: Expression profiling using microarrays was applied to peripheral blood mononuclear cell (PBMC) samples obtained from patients with advanced colorectal cancer participating in a Phase III clinical trial. The PBMC samples were harvested pre-treatment and at the end of the first 6-week cycle from patients receiving standard of care chemotherapy or standard of care plus SU5416, a vascular endothelial growth factor (VEGF) receptor tyrosine kinase (RTK) inhibitor. Results from matched pairs of PBMC samples from 23 patients were queried for expression changes that consistently correlated with SU5416 administration. RESULTS: Thirteen transcripts met this selection criterion; six were further tested by quantitative RT-PCR analysis of 62 additional samples from this trial and a second SU5416 Phase III trial of similar design. This method confirmed four of these transcripts (CD24, lactoferrin, lipocalin 2, and MMP-9) as potential biomarkers of drug treatment. Discriminant analysis showed that expression profiles of these 4 transcripts could be used to classify patients by treatment arm in a predictive fashion. CONCLUSIONS: These results establish a foundation for the further exploration of peripheral blood cells as a surrogate system for biomarker analyses in clinical oncology studies

A Phase I study of the angiogenesis inhibitor SU5416 (semaxanib) in solid tumours, incorporating dynamic contrast MR pharmacodynamic end points

SU5416 (Z-3-[(2,4-dimethylpyrrol-5-yl)methylidenyl]-2-indolinone; semaxanib) is a small molecule inhibitor of the vascular endothelial growth factor receptor (VEGFR)2. A Phase I dose escalation study was performed. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used as a pharmacodynamic assessment tool. In all, 27 patients were recruited. SU5416 was administered twice weekly by fixed rate intravenous infusion. Patients were treated in sequential cohorts of three patients at 48, 65, 85 110 and 145 mg m−2. A further dose level of 190 mg m−2 after a 2-week lead in period at a lower dose was completed; thereafter, the cohort at 145 mg m−2 was expanded. SU5416 showed linear pharmacokinetics to 145 mg m−2 with a large volume of distribution and rapid clearance. A significant degree of interpatient variability was seen. SU5416 was well tolerated, by definition a maximum-tolerated dose was not defined. No reproducible changes were seen in DCE-MRI end points. Serial assessments of VEGF in a cohort of patients treated at 145 mg m−2 did not show a statistically significant treatment-related change. Parallel assessments of the impact of SU5416 on coagulation profiles in six patients showed a transient effect within the fibrinolytic pathway. Clinical experience showed that patients who had breaks of therapy longer than a week could not have treatment reinitiated at a dose of 190 mg m−2 without unacceptable toxicity. The 145 mg m−2 dose level is thus the recommended dose for future study