Experimental assessment of ignition characteristics of lubricating oil sprays related to low-speed pre-ignition (LSPI)

This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/14680874211013268[EN] Low-speed pre-ignition (LSPI) remains one of the challenges of Direct Injection (DI) Spark Ignition (SI) engines due to its potential to induce a heavy knock. Several mechanisms have been identified in the literature as plausible causes for LSPI. The physical and chemical properties of lubricant oils play a role on some of these causes. The present work aims at getting an independent procedure to determine the proneness of lubricant oils to ignite. To this end, the ignition delay (ID) of different oil formulations is experimentally determined in a constant-pressure flow facility through two different optical techniques: Schlieren and OH* chemiluminescence imaging. The investigation explores the effect of base-stock formulation, oil specification quality level, different additive types content, aging, and oxidation on oil reactivity for several thermodynamic conditions. Differences in ignition delay were found among base stocks, correlating with the American Petroleum Institute (API) group classification. However, no significant differences were found among additive packages previously reported to yield different LSPI occurrences. Hence, differences in reactivity among lubricating oil formulations are not the determining factor explaining their different LSPI occurrences in an engine. Similarly, specific lubricant additive content, aging, and oxidation do not importantly modify the measured ignition delay.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Part of the experimental hardware used in this work was purchased through funds obtained from IDIFEDER/2018/037 ``Diagnostico optico a alta velocidad para el estudio de procesos termo-fluidodinamicos en sistemas de inyeccion.''Tormos, B.; García-Oliver, JM.; Carreres, M.; Moreno-Montagud, C.; Domínguez, B.; Cárdenas, MD.; Oliva, F. (2022). Experimental assessment of ignition characteristics of lubricating oil sprays related to low-speed pre-ignition (LSPI). International Journal of Engine Research. 23(8):1327-1338. https://doi.org/10.1177/146808742110132681327133823

Obesidad, inflamación e insulino-resistencia: papel de los ligandos del receptor gp 130

Obesity can be considered as a low grade inflammatory disease, characterized by increased plasma levels of proinflammatory cytokines such as tumoral necrosis factor-a (TNF-a), and acute phase reactant proteins like C-reactive protein. In this context, some cytokines of the interleukin-6 (IL-6) family have been involved in the inflammatory processes associated to obesity. In addition to IL-6, the IL-6 cytokine family includes IL-11, ciliary neurotrophic factor (cntf), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), leukemia inhibitory factor (LIF) y Oncostatin M (OsM). These proteins are also known as gp130 cytokines because all of them exert their action via the glycoprotein 130 (gp130) as a common transducer protein within their functional receptor complexes. However, their role in obesity and related disorders is controversial; thus, whereas some studies have described the involvement of gp130 cytokines in the development of obesity and its related cluster of pathophysiologic conditions like insulin-resistance, fatty liver and cardiovascular diseases, other trials have proposed the gp130 receptor ligands as therapeutic targets in the treatment of obesity and its related disorders. In fact, CNTF treatment has demonstrated to be effective in the reduction of body weight, by promoting the inhibition of food intake and the activation of the energy expenditure, together with an improvement of insulin sensitivity. This review analyzes the potential therapeutic role of some of the gp130 ligands in obesity and related diseases

Effects of eicosapentaenoic acid ethyl ester on visfatin and apelin in lean and overweight (cafeteria diet-fed) rats

Previous studies have demonstrated that the n-3 fatty acid EPA improves insulin resistance induced by high-fat diets. The aim of the present study was to investigate the potential role of visfatin and apelin in the insulin-sensitising effects of EPA ethyl ester. The effects of EPA on muscle and adipose GLUT mRNA, as well as on liver glucokinase (GK) and glucose-6-phosphatase (G6Pase) activity, were investigated. Male Wistar rats fed on a standard diet or a high-fat cafeteria diet were daily treated by oral administration with EPA ethyl ester (1 g/kg) for 5 weeks. A significant decrease (P,0·01) in white adipose tissue (WAT) visfatin mRNA levels was found in the cafeteria-fed rats, which was reversed by EPA administration (P,0·05). Moreover, a negative relationship was observed between homeostatic model assessment (HOMA) and the visfatin:total WAT ratio. In contrast, cafeteria-diet feeding caused a significant increase (P,0·01) in apelin mRNA in visceral WAT. EPA increased (P,0·01) apelin gene expression, and a negative relationship between HOMA index with visceral apelin mRNA and serum apelin:total WAT ratio was also observed. EPA treatment did not induce changes in skeletal muscle GLUT1, GLUT4 or insulin receptor mRNA levels. Neither liver GK and G6Pase activity nor the GK:G6Pase ratio was modified by EPA. These data suggest that somehow the insulin-sensitising effects of EPA could be related to its stimulatory action on both visfatin and apelin gene expression in visceral fat, while changes in skeletal muscle GLUT, as well as in hepatic glucose production, are not likely to be the main contributing factors in the improvement in insulin resistance induced by EPA

Interdisciplinary discussions on palliative care among university students in Spain: giving voice to the social debate

Background: University students are the future professionals who will influence society. It is thus essential to improve students' understanding of palliative care (PC), especially those in the non-health field, to generate and encourage propitious opinions about PC. This study describes the perceptions of PC among university students from different disciplines. Method: Qualitative exploratory study using virtual focus groups (FGs) and design thinking (DT) approach. An intentional sample of students from various disciplines, universities and cities from Spain were selected. Numerous researchers from different fields were involved in the discussion of the final thematic analysis. Results: Four themes and seven subthemes were found: i) Students have an ambiguous understanding about PC; ii) PC is not a common issue for non-health students; ii) Students see PC as an important and necessary field; iii) Students build counter-narratives against PC myths, demonstrating PC brings key benefits into people's lives; iv) PC is a synonym of death. Conclusion: Despite the fact that students do not know much about PC, the topic easily arouses reflection and positive discussion. Through the conversations they find positive values and arguments against misunderstand- ing. Students from different disciplines could be the target of innovative educational initia- tives and the social debate on PC

Aptamers against live targets: Is in vivo SELEX finally coming to the edge?

Targeted therapeutics underwent a revolution with the entry of monoclonal antibodies in the medical toolkit. Oligonucleotide aptamers form another family of target agents that have been lagging behind in reaching the clinical arena in spite of their potential clinical translation. Some of the reasons for this might be related to the challenge in identifying aptamers with optimal in vivo specificity, and the nature of their pharmacokinetics. Aptamers usually show exquisite specificity, but they are also molecules that display dynamic structures subject to changing environments. Temperature, ion atmosphere, pH, and other variables are factors that could determine the affinity and specificity of aptamers. Thus, it is important to tune the aptamer selection process to the conditions in which you want your final aptamer to function; ideally, for in vivo applications, aptamers should be selected in an in vivo-like system or, ultimately, in a whole in vivo organism. In this review we recapitulate the implementations in systematic evolution of ligands by exponential enrichment (SELEX) to obtain aptamers with the best in vivo activity

What does the media say about palliative care? A descriptive study of news coverage in written media in Spain

INTRODUCTION: The goal of palliative care (PC) is to improve the quality of life of terminal stage patients and their families. The subject frequently appears in the mass-media and this helps create a socially accepted identity. The aim of this study is to describe and analyse PC related news items appeared in the Spanish written media. METHODOLOGY: A descriptive cross-sectional study was designed. Considering diffusion, scope and the range in editorial policy criteria, four printed newspapers (PN) were selected, together with four exclusively digital media sources (DM). Through Mynews, a newspaper content depository, and the search tool for each DM website, articles published between 2009 and 2014 which included the terms "palliative care" and "palliative medicine" were sought. A questionnaire was created to characterise each article identified and a descriptive analysis was undertaken. RESULTS: A total of 627 articles were identified, of which 359 (57%) were published in PN (42% in the printed editions -PE- 16% in their online editions -OE-) and 268 (43%) in DM. In general, they appeared mainly in sections concerning Health (23%), Culture and Society (18%) and General/Home News (15%). In PE, just 2% were found in the Health section and nearly 70% in Culture and Society and General/Home News. Most of the articles were informative in nature and contained socio-political messages (90%). Statements by PC professionals were found in 35% of the articles and by politicians in 32%. The most frequent content was related to facing end of life (74%) and patient quality of life (70%). CONCLUSIONS: The Spanish written media reflects the socio-political interest aroused by PC. Nevertheless, messages circulating about PC do not describe professional practice, or the contribution of the same for patients. Content more in line with the clinical practice might help contribute to the development of this new area of medicine

Bradykinin or Acetylcholine as Vasodilators to Test Endothelial Venous Function in Healthy Subjects

INTRODUCTION: The evaluation of endothelial function has been performed in the arterial bed, but recently evaluation within the venous system has also been explored. Endothelial function studies employ different drugs that act as endothelium-dependent vasodilatory response inductors. OBJECTIVES: The aim of this study is to compare the endothelium-dependent venous vasodilator response mediated by either acetylcholine or bradykinin in healthy volunteers. METHODS AND RESULTS: Changes in vein diameter after phenylephrine-induced venoconstriction were measured to compare venodilation induced by acetylcholine or bradykinin (linear variable differential transformer dorsal hand vein technique). We studied 23 healthy volunteers; 31% were male, and the subject had a mean age of 33 ± 8 years and a mean body mass index of 23 ± 2 kg/m2. The maximum endothelium-dependent venodilation was similar for both drugs (p = 0.13), as well as the mean responses for each dose of both drugs (r = 0.96). The maximum responses to acetylcholine and bradykinin also had good agreement. CONCLUSION: There were no differences between acetylcholine and bradykinin as venodilators in this endothelial venous function investigation