[EN] Climate change is one of the short term threats for the humanity because it can affect seriously to the environment and, consequently, to vegetal and animal life. If it is not stopped in next years, maybe this effect will be irreversible. Climate change is produced by anthropogenic emissions of Greenhouse Gas to Earth's atmosphere. Vapour compression systems are one of the main contributors to this phenomenon. Among them, commercial refrigeration applications, through HFC usage, can be highlighted. Since 1990s, developed countries supermarkets are using refrigerants (mainly R134a, R404A and R507A) with great impact (high GWP values) on the climate change due to leakages, especially from parallel compressor rack DX systems. Recently, some regulations and directives have been approved to limit GWP values of HFC used in most extended refrigeration and air conditioning applications, directly affecting to commercial refrigeration. In this thesis, some low-GWP alternatives to replace the most commonly used HFC refrigerants in commercial refrigeration are evaluated, taking into account the limitations imposed by these regulations. To carry out this evaluation, the current status of parallel compressor rack refrigeration systems and their fluids has been reviewed. Then, the different low-GWP options to replace R134a and R404A have been studied. HFOs and their mixtures with HFC have been highlighted as the most promising drop-in or retrofit alternatives. Thus, R1234yf, R1234ze(E) and R450A were proposed to replace R134a and R448A to substitute R404A. The theoretical performance of the different low-GWP alternative fluids, as an overview of their potential use, has been studied at typical parallel compressor rack refrigeration operating conditions using the basic thermodynamic vapour compression cycle. Given the good theoretical performance of these refrigerants, they have been tested in a vapour compression test bench. From the experimental results it is depicted that R1234yf and R1234ze(E) are not acceptable as drop-in or light retrofit refrigerants from an energetic point of view. These fluids, when used in R134a systems, require system modifications (more severe in the case of R1234ze(E)) to achieve acceptable energy efficiency values. Moreover, due to the large refrigerant charge in PCRRS, both HFOs could present problems relating to security. Thus, while R450A presents a GWP value of 547, it appears as the best option to replace R134a due to the similar energy efficiency and properties. Its experimental mass flow rate and cooling capacity are slightly lower than R134a, but the final COP is approximately the same. The best R450A results when compared to R134a are obtained at higher CRs. Although can obtain better efficiency results in new systems, with a minor TXV adjustment R448A shows very high performance when it is used in R404A systems. Despite R448A lower cooling capacity than that R404A, this HFC/HFO mixture can achieve great CO2 equivalent emission reductions and it is recommended as lower-GWP replacement for R404A. / [ES] El cambio climático es una amenaza para la humanidad ya que puede afectar seriamente al medio ambiente y, en consecuencia, a la vida animal y vegetal. Si en los próximos años no se actúa para detenerlo, tal vez este efecto sea irreversible. Entre otros factores, el incremento de la temperatura global es producido por las emisiones antropogénicas de gases de efecto invernadero a la atmósfera. La refrigeración comercial, basada en sistemas de compresión de vapor, contribuye de forma relevante a este fenómeno a través del uso de fluidos sintéticos como refrigerantes y del consumo de energía eléctrica procedente de combustibles fósiles. Desde la última década del siglo XX, los supermercados de países desarrollados utilizan HFCs como fluidos de trabajo, principalmente R134a, R404A y R507A. Estos gases, de alto potencial de calentamiento atmosférico (PCA), contribuyen al cambio climático al fugarse accidentalmente de los sistemas de refrigeración, destacando las centrales de compresores en paralelo conectadas a sistemas de expansión directa. El valor máximo de PCA de los HFCs utilizados en aplicaciones de refrigeración y aire acondicionado va a ser controlado por normativas comunitarias, afectando directamente a los fluidos usados comúnmente en refrigeración comercial. Esta tesis evalúa diferentes alternativas de bajo PCA para sustituir los refrigerantes HFC más utilizados en refrigeración comercial, teniendo en cuenta las limitaciones impuestas por las normativas actuales. Para llevar a cabo dicho estudio, se revisa el estado actual de los sistemas de centrales de compresores en paralelo y sus fluidos. A continuación, se analizan las diferentes opciones de bajo PCA para sustituir al R134a y R404A. Al destacar los HFOs y sus mezclas con HFCs como alternativas para realizar un reemplazo con pocas modificaciones del sistema (propiedades similares); R1234yf, R1234ze(E) y R450A son propuestos para sustituir al R134a y R448A para R404A. El rendimiento teórico de los diferentes fluidos alternativos de bajo PCA, para obtener una visión general del potencial de su uso, se estudia simulando las condiciones operativas típicas de las centrales de compresores en paralelo, usando el ciclo termodinámico de compresión de vapor básico. Dado el buen rendimiento mostrado por estos refrigerantes, son ensayados en un banco de pruebas de compresión de vapor. De los resultados experimentales se observa que R1234yf y R1234ze(E) no son aceptables desde un punto de vista energético como sustitutivos directos o con menores modificaciones. Dichos fluidos, cuando son utilizados en sistemas de R134a, requieren modificaciones del sistema (más severas en el caso del R1234ze(E)) para alcanzar valores aceptables de eficiencia energética. Por otra parte, debido a la gran carga necesaria en PCRRS, ambos HFOs podrían presentar problemas en cuanto a la seguridad. Así, mientras que el R450A presenta un valor de PCA de 547, aparece como la mejor opción para sustituir al R134a debido a una eficiencia energética y propiedades similares. El caudal másico y la capacidad frigorífica del R450A son ligeramente inferiores en comparación con las del R134a, pero por otra parte, el COP resultante es aproximadamente el mismo. Los mejores resultados obtenidos para R450A son obtenidas a altas tasas de compresión. Aunque puede ser obtenida una eficiencia energética más alta en sistemas de nuevo diseño, con sólo un ajuste menor de la válvula de expansión termostática, el R448A muestra valores muy altos de rendimiento en sistemas utilizados con R404A. A pesar de que la capacidad frigorífica del R448A es menor que la del R404A, esta mezcla de HFC y HFO puede dar lugar a grandes reducciones de emisiones de CO2 equivalentes, siendo así recomendado como reemplazo del R404A con menor PCA. / [CA] El canvi climàtic és una amenaça per a la humanitat ja que pot afectar seriosament el medi ambient i, en conseqüència, la vida animal i vegetal. Si en els propers anys no s'actua per aturar-lo, potser aquest efecte siga irreversible. Entre altres factors, l'increment de la temperatura global és produït per les emissions antropogèniques de gasos d'efecte hivernacle a l'atmosfera. La refrigeració comercial, basada en sistemes de compressió de vapor, contribueix de manera rellevant a aquest fenomen per l'ús de fluids sintètics com refrigerants i pel consum d'energia elèctrica procedent de combustibles fòssils. Des de l'última dècada del segle XX, els supermercats dels països desenvolupats utilitzen HFCs com fluids de treball, principalment R134a, R404A i R507A. Aquests gasos, d'alt potencial d'escalfament atmosfèric (PCA en castellà), contribueixen al canvi climàtic quan s'escapen accidentalment dels sistemes de refrigeració. D'aquest tipus de sistemes destaquen com a grans emissors de diòxid de carboni les centrals de compressors en paral·lel connectades a sistemes d'expansió directa. El valor màxim de PCA dels HFCs utilitzats en aplicacions de refrigeració i aire condicionat serà controlat per normatives comunitàries, cosa que afectarà directament els fluids utilitzats a la gran majoria de sistemes de refrigeració comercial. Aquesta tesi avalua diferents alternatives de baix PCA per substituir els refrigerants HFC més utilitzats en refrigeració comercial sense oblidar les limitacions imposades per les normatives actuals. Per dur a terme aquest estudi, es revisa l'estat actual dels sistemes de centrals de compressors en paral·lel i els seus fluids. A continuació, s'analitzen les diferents opcions de baix PCA per substituir l'R134a i l'R404A. Els HFOs i les seves mescles amb HFCs com alternatives destaquen per permetre una substitució amb poques modificacions del sistema (propietats similars); R1234yf, R1234ze(E) i R450A són proposats per substituir l'R134a i R448A per l'R404A. Per obtenir una visió general del potencial de l'ús dels diferents fluids alternatius de baix PCA, s'estudia el seu rendiment teòric mitjançant una simulació de les condicions operatives típiques de les centrals de compressors en paral·lel. Per a aquesta simulació s'empra el cicle termodinàmic de compressió de vapor bàsic. Com a conseqüència del bon rendiment mostrat per aquests refrigerants, són assajats en un banc de proves de compressió de vapor. Dels resultats experimentals s'observa que R1234yf i R1234ze(E) no són acceptables des d'un punt de vista energètic com a substitutius directes o amb menors modificacions. Aquests fluids, quan són utilitzats en sistemes de R134a, requereixen modificacions del sistema (més severes en el cas de l'R1234ze(E)) per assolir valors acceptables d'eficiència energètica. D'altra banda, a causa de la gran càrrega necessària en PCRRS, tots dos HFOs podrien presentar problemes en temes de seguretat. Així, mentre que el R450A presenta un valor de PCA de 547, apareix com la millor opció per substituir l'R134a a causa de una eficiència energètica i propietats similars. El cabal màssic i la capacitat frigorífica de l'R450A són lleugerament inferiors en comparació amb les de l'R134a, però d'altra banda, el COP resultant és aproximadament el mateix. Els millors resultats de l'R450A són obtinguts a altes taxes de compressió. Tot i que pot ser obtinguda una eficiència energètica més alta en sistemes de nou disseny, amb només un ajust menor de la vàlvula d'expansió termostàtica, l'R448A mostra valors molt alts de rendiment en sistemes utilitzats amb R404A. Encara que la capacitat frigorífica de l'R448A és menor que la de l'R404A, aquesta barreja de HFCs i HFO pot aconseguir grans reduccions d'emissions de CO2 equivalents, i es per tant es recomanada com a reemplaçament amb menor PCA de l'R404A. / Mota Babiloni, A. (2016). ANALYSIS OF LOW GLOBAL WARMING POTENTIAL FLUORIDE WORKING FLUIDS IN VAPOUR COMPRESSION SYSTEMS. EXPERIMENTAL EVALUATION OF COMMERCIAL REFRIGERATION ALTERNATIVES [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62680 / Premios Extraordinarios de tesis doctorales

Extended reality (XR) technology is positioned to become more ubiquitous in life and the workplace in the coming decades, but the problem of how to best perform precision text-entry in XR remains unsolved. Physical QWERTY keyboards are the current standard for these kind of tasks, but if they are recreated virtually, the feedback information from sense of touch is lost. We designed and ran study with 24 participants to explore the effects of using auditory feedback to communicate this missing information that typists normally get from touching a physical keyboard. The study encompassed four VR mid-air keyboards with increasing levels of auditory information, along with a fifth physical keyboard for reference. We evaluated the auditory augmentations in terms of performance, usability, and workload, while additionally assessing the ability of our technique to communicate the touch-feedback information. Results showed that providing clicking feedback on key-press and key-release improves typing compared to not providing auditory feedback, which is consistent with literature on the topic. However, we also found that using audio to substitute the information contained in physical-touch feedback, in place of actual physical-touch feedback, yielded no statistically significant difference in performance. The information can still be useful, but potentially would take a lot of time to develop the muscle memory reflexes that typists already have when using physical keyboards to type. Nonetheless, we recommend others consider incorporating auditory feedback of key-touch into their mid-air keyboards, since it received the highest levels of user preference among keyboards tested. / Master of Science / Extended reality (XR) refers to technology that allows users to either immerse themselves in virtual worlds or incorporate virtual objects into the real world. XR is positioned to become more ubiquitous in life and the workplace in the coming decades, but the problem of how to best perform precision text-entry in XR remains unsolved. Physical QWERTY keyboards are the current standard for these kind of tasks, but if they are recreated virtually, the information inherent to sense of touch is lost. We designed and ran study with 24 participants to explore the effects of using auditory feedback to communicate this missing information that typists normally get from touching a physical keyboard. The study encompassed four virtual reality (VR) mid-air keyboards with increasing levels of auditory information, along with a fifth physical keyboard for reference. We evaluated the auditory augmentations in terms of performance, usability, and workload, while additionally assessing the ability of our technique to communicate the touch-feedback information. Results showed that providing clicking feedback on key-press and key-release improves typing compared to not providing auditory feedback, which is consistent with literature on the topic. However, we also found that using audio to substitute the information contained in physical-touch feedback, in place of actual physical-touch feedback, yielded no statistically significant difference in performance. The information can still be useful, but potentially would take a lot of time to develop the muscle memory reflexes that typists already have when using physical keyboards to type. Nonetheless, we recommend others consider incorporating auditory feedback of key-touch into their mid-air keyboards, since it received the highest levels of user preference among keyboards tested.

Doctor of Philosophy / Filtered Rayleigh scattering (FRS) is a laser-based measurement technique that makes use of the scattering of light off particles that are much smaller than the wavelength of light that hits them (i.e., Rayleigh scattering of air molecules). The scattered laser light is altered after encountering particles in predictable ways that can be related to changes in velocity, temperature, and density. However, other sources of scattered light interfere with the pure Rayleigh scattering signal such as Mie and background scattering. Mie scattering is the scattering of light off particles that are much bigger than the wavelength of light that hits them (i.e., dust particles suspended in air). Background scattering is the laser light scattered off physical objects that reflect back into the region of interest. The different types of scattering are accounted for with intensive modeling and iterative fitting schemes where the error between simulated data and experimental data is minimized. This fit allows for velocity, temperature, and density information to be extracted from the measured scattered light. This iterative scheme is then applied to experimental measurements on the ground with mini turbojet engines as well as full-scale turbofan engines. A data grouping technique is derived such that the total measured force using FRS can be divided into individual contributions from different parts of the engine. These developed techniques have laid the foundation for future in-flight measurements of engine forces.

Aortic stenosis (AS) is a critical valvular disease often treated by Transcatheter Aortic Valve Replacement (TAVR). This thesis introduces several novel approaches for improving the assessment and management of AS and the associated TAVR procedure. The research presents new indices for characterizing AS progression, including the False Positive Rate (FPR) method for detecting and quantifying calcification in contrast-enhanced computed tomography (CT) images. This method adapts dynamically to the variability in calcium density and offers precise estimates of calcific burden. Additionally, a Minimal Variation Geometry Invariant Parametric Reconstruction (MVGIPR) method was developed to reconstruct the full geometry of the aortic valve complex (AVC). This approach enhances the accuracy of geometric models from routine CT scans, providing detailed 3D models of the aortic valve, including patient-specific anatomical and pathological features. Moreover, the Virtual Transcatheter Aortic Valve Replacement (VTAVR) framework is introduced for TAVR optimization and intervention planning using developments from both previous techniques. This novel simulation-based system incorporates kinematic modeling within a patient-specific parametric geometry to predict device deployment outcomes, including complications such as paravalvular leakage, patient-prosthesis mismatch, and left bundle branch block. By simulating patient-specific device deployment, the VTAVR framework may potentially enhance pre-procedural planning, leading to better surgical outcomes and reduced risks in TAVR procedures. / Thesis / Doctor of Philosophy (PhD) / Aortic stenosis (AS) is a condition where the heart’s aortic valve becomes narrowed due to calcification, restricting blood flow and leading to severe health risks, especially in older adults. This research introduces new ways to measure the progression of this disease and predict complications from the commonly used treatment called Transcatheter Aortic Valve Replacement (TAVR). Using advanced computational models, the study develops personalized aortic valve shape and structure assessment frameworks using routine clinical computed tomography (CT) imaging. Moreover, we introduce a virtual interventional simulation framework that can predict how a patient’s valve may respond to TAVR. This "Virtual TAVR" system may help treating physicians to plan surgeries more accurately by simulating different approaches, allowing them to identify the best treatment strategy for each patient. By improving our ability to predict complications, the system ultimately aims to increase the success rate of these life-saving procedures.

Yes / The thermodynamic stability of caffeine (CA) cocrystals with dicarboxylic acids (DAs) as coformers was investigated in the presence of a range of structurally related dicarboxylic acids (SRDs). Two experimental conditions (slurry and dry-grinding) were studied for mixing the cocrystal and the SRD additive. The additives oxalic, malonic and glutaric acid led to the replacement of the acid coformer for certain cocrystals. Interestingly, a change in stoichiometry was observed for the CA:maleic acid system. A stability order among the cocrystals was established depending on their tendency to replace the coformer. To understand the factors controlling the relative stabilities, lattice energies were calculated using dispersion corrected Density Functional Theory (DFT). Gibbs free energy changes were calculated from experimental solubilities. The observed stability order corroborated well with lattice energy and Gibbs free energy computations.

Yes / Less than optimal particle isolation techniques have impeded analysis of orthopaedic wear debris in vivo. The purpose of this research was to develop and test an improved method for particle isolation from tissue. A volume of 0.018 mm3 of clinically relevant CoCrMo, Ti-6Al-4V or Si3N4 particles was injected into rat stifle joints for seven days of in vivo exposure. Following sacrifice, particles were located within tissues using histology. The particles were recovered by enzymatic digestion of periarticular tissue with papain and proteinase K, followed by ultracentrifugation using a sodium polytungstate density gradient. Particles were recovered from all samples, observed using SEM and the particle composition was verified using EDX, which demonstrated that all isolated particles were free from contamination. Particle size, aspect ratio and circularity were measured using image analysis software. There were no significant changes to the measured parameters of CoCrMo or Si3N4 particles before and after the recovery process (KS tests, p > 0.05). Titanium particles were too few before and after isolation to analyse statistically, though size and morphologies were similar. Overall the method demonstrated a significant improvement to current particle isolation methods from tissue in terms of sensitivity and efficacy at removal of protein, and has the potential to be used for the isolation of ultra-low wearing total joint replacement materials from periprosthetic tissues.

No / MicroRNAs are a relatively new class of small, noncoding RNA species that represent a cornerstone of cell biology, with diverse roles ranging from embryonic development to aging. miRNAs function to regulate posttranscriptional gene expression, are critical to the normal function of cells, and as such are frequently dysregulated during disease processes. In this chapter, we discuss the biogenesis and mechanism of action of miRNA and their role in cancer initiation, promotion, and progression. In addition, we discuss the most recently identified dual roles of miRNA in epigenetic gene regulation; how they are both regulators and regulated. Finally, we discuss the emerging roles of miRNA as epigenetic anti-cancer therapeutics, the current research examining inhibition of oncogenic miRNAs, and studies now establishing the potential of replacing lost, tumor-suppressive miRNA.

This study can be classified under the subject of equipment item replacement analysis. Simultaneous failure, SF, of the components of an equipment item, EI, is the topic of this thesis. Examination of the possibility of designing components of an EI for SF is one objective of the study. The motive for this objective is the belief that SF designs of EI minimize the total cost of acquiring and operating the EI. Examination of the strength of materials reveals that design life of components is not sufficiently flexible to realize SF, and design requirements can predetermine design life. This is true for mechanical components such as links, gears, and bearings. Hence it was concluded that SF of the mechanical components of an EI, cannot be easily achieved. The second objective of the study was to formulate a model for optimizing the design of the components of an EI with life considerations. A mechanical reliability model was first modified by the inclusion of fatigue stress-strength relationships, and the theory of Cumulative Damage. By mathematical manipulation to suit the principles of Lagrange's Method of Undetermined Multipliers, an optimization model has been developed. This model enables system and component design constraints and requirements to be included in the optimization process. / Master of Science

The aim of the study is to investigate how young men constructing identities in talk about their own use of violence. The study is based on a fieldwork at a youth detention home in Sweden. The data consists of individual interviews and video recordings of the treatment programme Aggression Replacement Training (ART). Detailed analyses have been made of conversations between the young men, between the young men and the trainers, and of the narratives generated in the individual interviews. The study has a social constructionist approach to identity, which is seen as constructed in a joint achievement in social interaction. An important analytical perspective in the study is how social categories and subcategories are constructed. The study has a particular focus on gender, primarily masculinity, but age and ethnicity are also being emphasised. The analysis draws on four empirical studies. It is shown how the young men construct a preferred self-presentation when talking about violent events. The narratives on violence are either based on experiences or talked about as a hypothetical use of violence. Violence based on personal experience is problematized and legitimized in terms of self-defence, defending friends, restraint and justified violence. Narratives of violence are shown to be interactional resources available to the young men. When talking about violence, the young men can be seen to regulate social relations, and to position themselves in relation to particular discourses of masculinity. The specific understanding of what it entails to be a man enables the use of violence with respect to social categorizations such as age, ethnicity or criminal identity. It is also argued that the treatment programme ART may, at times, facilitate maintaining a criminal identity. / Avhandlingens övergripande syfte är att undersöka hur unga män konstruerar identiteter kring berättelser om eget våldsutövande. Den bygger på en studie gjord vid ett särskilt ungdomshem i Sverige. Såväl enskilda intervjuer som videoinspelningar av behandlingsprogrammet Aggression Replacement Training (ART) har utgjort analysmaterialet. Ingående analyser har gjorts av samtalen mellan de unga männen, mellan de unga männen och behandlingspersonalen, och berättelserna i de enskilda intervjuerna. Avhandlingen bygger på en socialkonstruktionistisk ansats där identitet analyseras i social interaktion med andra. Ett viktigt analytiskt perspektiv i studien är hur sociala kategorier och underkategorier skapas. Ett särskilt fokus ligger på genus och då främst maskulinitet, men även ålder och etnicitet lyfts fram som viktiga perspektiv. Avhandlingen omfattar fyra delstudier. Studien visar hur de unga männen konstruerar en positiv självpresentation när de talar om våldshändelser. Våldsberättelserna är antingen erfarenhetsbaserade eller utgår ifrån tal om hypotetiskt våld. Det erfarenhetsbaserade våldet problematiseras och legitimeras genom att talas om som självförsvar, försvar av kompisar, återhållsamt eller rättmätigt. Studien visar att våldsberättelser är interaktionella resurser för de unga männen. Genom att tala om våld reglerar de sociala relationer och positionerar sig i relation till vissa maskulinitetsdiskurser. Den specifika förståelsen av vad det innebär att vara en man, möjliggör användandet av våld avhängigt andra sociala kategorier, så som ålder, etnicitet och kriminell identitet. Studien indikerar också att behandlingsprogrammet ART ger möjlighet att underlätta upprätthållandet av en kriminell identitet. / <p>Due to copyright matters, have the articles, published in chapter 4, 5, 6 and 7, been removed.</p>

INTRODUÇÃO: A rigidez arterial é fator de risco cardiovascular pouco estudado e importante determinante de sobrecarga cardiovascular, estando associada ao envelhecimento. Analisou-se a ação das terapêuticas com estrogênios eqüinos conjugados (EEC) ou raloxifeno sobre os índices de rigidez, com o intuito de se observar a influência destas medicações na rigidez arterial, bem como se as mesmas são capazes de influenciar o envelhecimento vascular bem sucedido. MÉTODOS: Realizou-se estudo duplo cego, randomizado, placebo-controlado, que envolveu sessenta e sete mulheres saudáveis, normotensas e com 1 a 10 anos de menopausa, divididas em três grupos de 24, 25 e 18 mulheres. Estas receberam placebo, 0,625 mg EEC ou 60 mg de raloxifeno, respectivamente, 1 comprimido por dia, por 4 meses consecutivos. Analisou-se a rigidez arterial, através da avaliação das velocidades de onda de pulso carótida-femoral (VOP CF), fêmoro-pediosa (VOP FP), e do índice de amplificação (IA) da pressão sistólica na artéria carótida. RESULTADOS: Não se observou qualquer alteração dos índices de rigidez arterial associada às intervenções farmacológicas no grupo placebo (VOP CF pré x pós: 644 x 626 cm/s, p= 0,09; VOP FP pré x pós: 1006 x 1012 cm/s, p= 0,77; IA pré x pós = 30 x 29%, p= 0,55), no grupo EEC (VOP CF pré x pós: 642 x 600 cm/s, p= 0,11; VOP FP pré x pós: 952 x 971 cm/s, p= 0,66; IA pré x pós: 25 x 32%, p= 0,82) e no grupo raloxifeno (VOP CF pré x pós: 636 x 601 cm/s, p= 0,12; VOP FP pré x pós: 964 x 941 cm/s, p= 0,62; IA pré x pós:25 x 25%, p= 0,65). Apesar da ausência de ação das drogas sobre a rigidez arterial, houve uma correlação significativa entre o grau de rigidez arterial basal e a resposta à intervenção farmacológica, particularmente no grupo EEC, de tal maneira que a redução dos índices de rigidez neste grupo foi proporcional ao nível de rigidez basal, apresentando as seguintes relações: VOP CF (r= -0,602, p= 0,001); VOP FP (r= -0,455, p= 0,022); IA (r= -0,410, p= 0,042). CONCLUSÃO: EEC e raloxifeno não parecem afetar a rigidez arterial de mulheres sadias e normotensas com menos de 10 anos de menopausa / INTRODUCTION: Arterial stiffness has been recognized as a cardiovascular risk factor, an important determinant of the left ventricular overload and a marker of cardiovascular aging. However, the clinical impact of arterial stiffness and how it is affected by hormone therapy has not been fully investigated. This study analyzed the influence of conjugated equine estrogens (CEE) or raloxifene on arterial stiffness and how the may influence successful cardiovascular aging. METHODS: Sixty-seven healthy and normotensive women with 1 to 10 years of menopause were randomly assigned to one of three groups, with 24, 25, and 18 participants. They were given oral placebo, 0,625 mg of conjugated equine estrogen, or 60 mg of raloxifene, respectively, for 4 consecutive months. Arterial stiffness was evaluated by measurement of the carotid-femoral pulse wave velocity (PWV CF) and femoral-dorsalis pedis pulse wave velocity (PWV FP), and the systolic pressure augmentation index (AI) at the carotid artery obtained by applanation tonometry. RESULTS: None of the treatment regimens affected arterial stiffness: placebo (PWV CF before x after: 644 x 626 cm/s, p= 0.09; PWV FP before x after : 1006 x 1012 cm/s, p= 0.77; AI before x after = 30 x 29%, p= 0.55), CEE (PWV CF before x after: 642 x 600 cm/s, p= 0.11; PWV FP before x after: 952 x 971 cm/s, p= 0.66; AI before x after: 25 x 32%, p= 0.82) and raloxifene (PWV CF before x after: 636 x 601 cm/s, p= 0.12; PWV FP before x after: 964 x 941 cm/s, p= 0.62; AI before x afer:25 x 25%, p= 0.65). Despite the absence of statistically significant reduction in arterial stiffness with treatment, there was a significant correlation between basal stiffness and the degree of reduction in the indexes measured, indicating that the higher the basal stiffness, the greater the degree of reduction, particularly in the CEE group: PWV CF (r= -0.602, p= 0.001); PWV FP (r= -0.455, p= 0.022); AI (r= -0.410, p= 0.042). CONCLUSIONS: Conjugated equine estrogen and raloxifene do not seem to affect arterial stiffness of healthy normotensive women with less than 10 years of menopause