Effects of vibrations applied to fluids at different gravity levels

Due to the increasing interest in space exploration, management of two-phase flows in the absence of gravity has become a key aspect in improving the efficiency of technological applications for space missions. Understanding of two-phase flows is essential in the development of future applications and for the improvement of existing ones, not only in microgravity, but also in hypergravity conditions. In this thesis, the effects of external factors such as high and low frequency vibrations, or rotations on two-phase flows are addressed, when these systems are at different gravity levels. A series of experimental setups were developed in order to explore a wide range of phenomena occurring at different gravity levels. The effects of pressure fields on micron-sized particles in the levitation plane of an acoustic field are discussed. Furthermore, an analysis of the motions of two isolated particles is provided and a method to determine the forces between them is presented. The method allows us to experimentally obtain the order of magnitude of the forces, as well as indirectly provide a measurement of the acoustic pressure inside a micro-channel. Two microgravity experiments adapted to a sub-orbital vehicle were designed and built in order to examine the effects of low frequency vibrations and rotation in two-phase flows. This thesis will further analyse the effects observed in bubbles in different liquids. Bubble shape oscillations have been observed at low vibration frequencies, even though bubble dynamics are affected by the walls of the cell. After vibrations were turned off, the aspect ratio of a bubble in high viscosity fluid decays exponentially. Bubble break-up has been observed in the case of lower surface tension and lower viscosity. Focusing on the distribution of the air bubbles during high and low rotation rates, an analysis is presented on the effects on a low surface tension fluid. An investigation is presented on the injection trajectory of bubbles during rotation showing a reasonable agreement with analytical predictions. The detachment and rise of bubbles and bubble trains while an acoustic field is applied in hypergravity conditions are also addressed. Different effects have been observed in this experiment. Focusing on detachment, we provide an expression for estimating the detachment diameter when an acoustic field is applied. In addition, the effect of bubble trains on terminal velocity is discussed. A numerical analysis is also presented and compared to the experimental data.Degut a l'increment en l'interès per l'exploració espacial, la gestió de fluids bifàsics en absència de gravetat ha esdevingut un tema clau per la millora de l'eficiència d'aplicacions tecnològiques per a missions espacials. Arribar a entendre els fluids bifàsics és important per al desenvolupament de futures aplicacions i per la millora de les ja existents, no només en condicions de microgravetat sinó també en condicions d'hipergravetat. En aquesta tesi es tracten els efectes que tenen factors externs com vibracions d'alta i baixa freqüència o rotacions, sobre fluids bifàsics, quan aquests es troben en diferents nivells de gravetat. S'han desenvolupat una sèrie de muntatges experimentals per a explorar els diferents fenòmens que succeeixen a diferents nivells de gravetat. S'analitzen els efectes que tenen els camps de pressió sobre partícules micromètriques en el pla de levitació d'un camp acústic. A més, s'analitza el moviment de dues partícules aïllades i es presenta un mètode per a determinar les forces entre elles. Aquest mètode permet obtenir experimentalment l'ordre de magnitud de les forces, així com obtenir indirectament la mesura de la pressió del camp acústic dins del micro canal. S'han dissenyat i muntat dos experiments de microgravetat adaptats a un vehicle suborbital, per estudiar els efectes de vibracions de baixa freqüència i rotació sobre fluid bifàsics. Es presenta una anàlisi dels efectes observats sobre les bombolles. S'han observat oscil·lacions de forma de les bombolles amb vibracions de baixa freqüència, tot i que la dinàmica es veu afectada per les parets de la cavitat. Després d'aturar la relació d'aspecte d'un fluid d'alta viscositat decreix exponencialment. També s'ha observat trencament de la bombolla, en el cas de baixa tensió superficial i baixa viscositat. Pel que fa a rotació, es fa un anàlisis dels efectes que té sobre un fluid de baixa tensió superficial, centrant-nos en la distribució de bombolles d'aire quan la velocitat de rotació és més alta o més baixa. S'estudia la trajectòria de les bombolles injectades durant la rotació, mostrant concordança amb prediccions analítiques. Per últim, abordem el desenganxament i l'ascens de bombolles i trens de bombolles, mentre apliquem un camp acústic en condicions d'hipergravetat. Durant els experiments s'han observat diferents efectes. Mirant el desenganxament, donem una expressió per estimar el diàmetre de la bombolla quan es desenganxa quan s'està aplicant un camp acústic. A més, es discuteixen els efectes sobre trens de bombolles. També es presenta una anàlisi numèric i es compara amb les dades obtingudes experimentalment.Postprint (published version

A sounding rocket experiment to control boiling by means of acoustic waves

One of the most critical issues when considering long-term space exploration missions is the management and storage of cryogenic propellants. The exposure of storage tanks to radiation and extreme temperatures implies the need of efficient technologies to counteract their effects on the fuel. A potentially dangerous effect for spacecraft operations is the generation of vapor bubbles in cryogenic propellants. We present an experimental setup and procedure to mature a technology based on acoustic waves to control boiling in microgravity.Peer ReviewedPostprint (author's final draft

Biomimetic 3D models for investigating the role of monocytes and macrophages in atherosclerosis

Atherosclerosis, the inflammation of artery walls due to the accumulation of lipids, is the most common underlying cause for cardiovascular diseases. Monocytes and macrophages are major cells that contribute to the initiation and progression of atherosclerotic plaques. During this process, an accumulation of LDL-laden macrophages (foam cells) and an alteration in the extracellular matrix (ECM) organization leads to a local vessel stiffening. Current in vitro models are carried out onto two-dimensional tissue culture plastic and cannot replicate the relevant microenvironments. To bridge the gap between in vitro and in vivo conditions, we utilized three-dimensional (3D) collagen matrices that allowed us to mimic the ECM stiffening during atherosclerosis by increasing collagen density. First, human monocytic THP-1 cells were embedded into 3D collagen matrices reconstituted at low and high density. Cells were subsequently differentiated into uncommitted macrophages (M0) and further activated into pro- (M1) and anti-inflammatory (M2) phenotypes. In order to mimic atherosclerotic conditions, cells were cultured in the presence of oxidized LDL (oxLDL) and analyzed in terms of oxLDL uptake capability and relevant receptors along with their cytokine secretomes. Although oxLDL uptake and larger lipid size could be observed in macrophages in a matrix dependent manner, monocytes showed higher numbers of oxLDL uptake cells. By analyzing major oxLDL uptake receptors, both monocytes and macrophages expressed lectin-like oxidized low-density lipoprotein receptor-1 (LOX1), while enhanced expression of scavenger receptor CD36 could be observed only in M2. Notably, by analyzing the secretome of macrophages exposed to oxLDL, we demonstrated that the cells could, in fact, secrete adipokines and growth factors in distinct patterns. Besides, oxLDL appeared to up-regulate MHCII expression in all cells, while an up-regulation of CD68, a pan-macrophage marker, was found only in monocytes, suggesting a possible differentiation of monocytes into a pro-inflammatory macrophage. Overall, our work demonstrated that collagen density in the plaque could be one of the major factors driving atherosclerotic progression via modulation of monocyte and macrophages behaviors

Incidence and characteristics of adverse drug reactions in a cohort of patients treated with PD-1/PD-L1 inhibitors in real-world practice

Adverse reaction; Immunotherapy; PharmacovigilanceReacción adversa; Inmunoterapia; FarmacovigilanciaReacció adversa; Immunoteràpia; FarmacovigilànciaBackground: Data related to adverse drug reactions (ADRs), specifically immune-related adverse events (irAEs), in long-term treatment with immunotherapy in real-world practice is scarce, as is general information regarding the management of ADRs. Objectives: To characterize and describe the incidence of ADRs in patients who began immunotherapy treatment in clinical practice. Methods: In a prospective observational study cancer patients ≥18 years of age who were treated with a monotherapy regime of PD-1/PD-L1 inhibitors were evaluated. The study period was from November 2017 to June 2019 and patients were followed up until June 2021. Patients were contacted monthly by telephone and their electronic health records were reviewed. Each ADR was graded according to the Common Terminology Criteria for Adverse Events (CTCAE 5.0). Results: Out of 99 patients, 86 met the inclusion criteria. Most were male (67.4%), with a median age of 66 (interquartile range, IQR: 59–76). The most frequent cancer was non-small cellular lung cancer (46 cases, 53.5%), followed by melanoma (22, 25.6%). A total of 74 patients (86%) were treated with anti-PD-1 drugs and 12 (14%) were treated with anti-PD-L1 drugs. The median treatment durations were 4.9 (IQR: 1.9–17.0) and 5.9 months (IQR: 1.2–12.3), respectively. Sixty-three patients (73%) developed from a total of 156 (44% of the total number of ADR) irADRs, wherein the most frequent were skin disorders (50 cases, 32%, incidence = 30.5 irADRs/100 patients per year [p-y]), gastrointestinal disorders (29, 19%, 17.7 irADRs/100 p-y), musculoskeletal disorders (17, 11%, 10.4 irADRs/100 p-y), and endocrine disorders (14, 9%, 8.6 irADRs/100 p-y). A total of 22 irADRs (14%) had a latency period of ≥12 months. Twelve irADRs (7.7%) were categorized as grade 3–4, and while 2 (1.3%) were categorized as grade 5 (death). Sixty-one irADRs (39.1%) in 36 patients required pharmacological treatment and 47 irADRs (30.1%) in 22 patients required treatment with corticosteriods. Conclusion: The majority of patients treated with anti-PD1/PDL1-based immunotherapy experienced adverse reactions. Although most of these reactions were mild, 11.5% were categorized as grade 3 or above. A high percentage of the reactions were immune-related and occurred throughout the treatment, thereby indicating that early identification and close monitoring is essential

Age-dependency of the propagation rate of coronavirus disease 2019 inside school bubble groups in Catalonia, Spain

We analyzed contagions of coronavirus disease 2019 inside school bubble groups in Catalonia, Spain, in the presence of strong nonpharmaceutical interventions from September to December 2020. More than 1 million students were organized in bubble groups and monitored and analyzed by the Health and the Educational departmentPostprint (published version

Guia d’abordatge del delírium

Guia d'abordatge; Delírium; DemènciesGuía de abordaje; Delirium; DemenciasBoarding guide; Delirium; DementiasAquesta guia pretén ser el punt de referència per a professionals i per a l’entorn cuidador dels pacients amb delírium, alhora que estableix les recomanacions de prevenció, identificació i tractament que garanteixen una atenció òptima per als pacients, de manera que involucra l’entorn cuidador i reconeix la seva importància. L’objectiu d’aquesta guia és la creació d’una eina pràctica i accessible per a tothom que permeti minvar els efectes d’aquesta síndrome (la qual apareix sobtadament), i que sigui útil per a tots els nivells assistencials i per a l’àmbit social

Pla d’atenció sanitària a les persones amb deteriorament cognitiu lleu i demència de Catalunya (PLADEMCAT)

Atenció sanitària; Deteriorament cognitiu; Salut públicaAtención sanitaria; Deterioro cognitivo; Salud públicaHealth care; Cognitive impairment; Public healthEl Pla d’atenció sanitària a les persones amb deteriorament cognitiu lleu i demència de Catalunya, PLADEMCAT, està conformat per tres documents íntimament relacionats: estat de situació, model d’atenció i operativa. Tots tres tenen una estructura comuna corresponent a les diferents fases evolutives de les demències: la prevenció, el diagnòstic, el tractament integral i l’atenció al llarg de l’evolució de tota la malaltia fins a la fase de demència avançada i final de la vida de les persones. Així, en els tres documents hi ha els mateixos apartats, amb l’objectiu de mantenir un fil conductor comú.Aquest projecte ha estat financiat a càrrec dels fons per a les estratègies 2019 del Ministerio de Sanidad, Consumo y Bienestar Social que vàren ser aprovats en el CISNS de data 13 de desembre de 2019, com a recolzament a la implemenció de la estratègia davant les patologies neurodegeneratives (inclosa ELA)

Complements alimentaris: control oficial

Complements alimentaris; Control oficial; Guia; Seguretat alimentàriaComplementos alimenticios; Control oficial ; Guia; Seguridad alimentariaFood supplements; Official controls; Guide; Food safetyAquesta publicació pretén donar una visió general del control oficial dels complements alimentaris a Catalunya mitjançant el recull de les diferents fonts normatives i documentals existents relatives als complements alimentaris, amb la finalitat principal de tenir una eina de suport al personal de l’Agència de Salut Pública de Catalunya, així com a altres administracions i professionals del sector. A més, amb l’elaboració d’aquesta guia es vol ajudar a entendre què són els complements alimentaris i donar a conèixer què es fa des de les administracions públiques per mantenir la seguretat alimentària. El document s’estructura en diversos apartats, que inclouen la inscripció al registre sanitari de les empreses que comercialitzen complements alimentaris, la notificació d’aquests complements i la normativa aplicable, sense deixar d’aprofundir en aspectes relacionats amb la composició, l’envasament, l’etiquetatge, els contaminants i els criteris microbiològics. Aquesta guia inclou taules de consulta per identificar els ingredients que intervenen en la composició dels complements alimentaris i un protocol per a la revisió de l’etiquetatge correcte. Índe

Impact of the 2018 revised Pregnancy Prevention Programme by the European Medicines Agency on the use of oral retinoids in females of childbearing age in Denmark, Italy, Netherlands, and Spain: an interrupted time series analysis

Background: In March 2018, the European pregnancy prevention programme for oral retinoids was updated as part of risk minimisation measures (RMM), emphasising their contraindication in pregnant women. Objective: To measure the impact of the 2018 revision of the RMMs in Europe by assessing the utilisation patterns of isotretinoin, alitretinoin and acitretin, contraceptive measures, pregnancy testing, discontinuation, and pregnancy occurrence concomitantly with a retinoid prescription. Methods: An interrupted time series (ITS) analysis to compare level and trend changes after the risk minimisation measures implementation was conducted on a cohort of females of childbearing age (12-55 years of age) from January 2010 to December 2020, derived from six electronic health data sources in four countries: Denmark, Netherlands, Spain, and Italy. Monthly utilisation figures (incidence rates [IR], prevalence rates [PR] and proportions) of oral retinoids were calculated, as well as discontinuation rates, contraception coverage, pregnancy testing, and rates of exposed pregnancies to oral retinoids, before and after the 2018 RMMs. Results: From 10,714,182 females of child-bearing age, 88,992 used an oral retinoid at any point during the study period (mean age 18.9-22.2 years old). We found non-significant level and trend changes in incidence or prevalence of retinoid use in females of child-bearing age after the 2018 RMMs. The reason of discontinuation was unknown in >95% of cases. Contraception use showed a significant increase trend in Spain; for other databases this information was limited. Pregnancy testing was hardly recorded thus was not possible to model ITS analyses. After the 2018 RMM, rates of pregnancy occurrence during retinoid use, and start of a retinoid during a pregnancy varied from 0.0 to 0.4, and from 0.2 to 0.8, respectively. Conclusion: This study shows a limited impact of the 2018 RMMs on oral retinoids utilisation patterns among females of child-bearing age in four European countries. Pregnancies still occur during retinoid use, and oral retinoids are still prescribed to pregnant women. Contraception and pregnancy testing information was limited in most databases. Regulators, policymakers, prescribers, and researchers must rethink implementation strategies to avoid any pregnancy becoming temporarily related to retinoid use