Control and analysis of protein aggregation is an increasing challenge to biopharmaceutical research and development. Therefore it is important to understand the interactions, causes and analysis of particles in order to control protein aggregation to enable successful biopharmaceutical formulations. This work investigates the role of different non-ionic surfactants on protein conformational stability, as assessed by HSDSC, and on protein size stability as assessed by Dynamic Light Scattering (DLS), HIAC and MFI. BSA and IgG2 were used as model proteins. Thermal unfolding experiments indicated a very weak surfactant-immunoglobulin IgG2 interaction, compared to much stronger interactions for the BSA surfactant systems. The DLS results showed that BSA and IgG2 with different surfactants and concentration produced different levels of particle size growth. The heat treatment and aging of samples in the presence of Tween 20, Tween 80, Brij 35 and Pluronic F-68 surfactants led to an increase in the populations of larger particles for BSA samples, whereas IgG2 systems did not notably aggregate under storage conditions MFI was shown to be more sensitive than HIAC technique for measuring sub-visible particles in protein surfactant systems. Heat treatment and storage stress showed a significant effect on BSA and IgG2 protein sub-visible particle size stability. This work has demonstrated that both proteins with different Tween 20, Tween 80, Brij 35 and Pluronic F-68 concentrations, have different level of conformational and size stability. Also aging samples and heating stress bears the potential to generate particles, but this depends on surfactant type. Poor predictive correlations between the analytical methods were determined.

由於可攜式行動裝置近年來快速成長，隨著行動裝置與地理資訊的結合發展出的適地性服務 (Location-Based Service, LBS)，也呈現越來越多的應用方式。LBS最基本的功能為定位，定位精度好壞也影響著LBS的應用面，越高的定位精度應用面越廣。常見的定位方式便是用GPS導航定位，但是在都會地區越是繁榮的地方往往過多的建物使衛星訊號被阻擋，導致GPS的定位會受到影響，造成平面誤差量會在15公尺以上，或是無法定位。利用都市區域有Wi-Fi訊號分布的特性，藉由區分不同的Wi-Fi訊號來源與接收強度，做出定位判斷，可以使原本GPS無法定位的區域，也可以利用Wi-Fi訊號來做定位。本研究嘗試使用高感度GPS接收器，在建物周邊定位，及在GPS無法運作時使用Wi-Fi訊號來做定位依據，提高整體的定位成功率，並嘗試利用Wi-Fi定位與GPS協同運作來提高整體精度。Wi-Fi定位採用訊號紋辨識法，欲使用訊號紋辨識法必先建立Wi-Fi訊號資料庫，包含地理坐標與對應的訊號來源與強度分布。實驗區為政治大學山下校區綜合院館四周面積約1.76公頃區域，模擬被遮蔽狀況下的GPS導航定位精度，配合Wi-Fi定位來輔助GPS定位結果。結果顯示利用兩種定位系統，可使平面平均定位誤差小於10公尺，高程平均定位誤差小於1.5公尺。 / The positioning accuracy is an important issue for Location-Based Service (LBS). LBS has many products, and its applications are usually based on Global Positioning System (GPS), because GPS navigation has been very mature. GPS has a typical outdoor positioning error of up to 15 meters for civilian users. Hence it has become a viable method for civilian to carry out coarse positioning. However, it has its shortcomings. GPS is available only in outdoors with a clear view of the sky. Since Wi-Fi (Wireless Fidelity) has become another positioning technology which is capable of performing positioning in indoor environments and urban canyons. Wi-Fi positioning is using fingerprinting in this study. This study is desirable to integrate GPS and Wi-Fi positioning technologies for ubiquitous positioning. The related issues of Wi-Fi/GPS technologies, such as database quality, analysis of algorithms, and database processing procedures were studied. Test data sets from National Chengchi University (NCCU) campus will be used to test the proposed algorithms. By using those two positioning system , it is revealed that the positioning accuracy made at the test sites resulted that the 2D coordinate average error is less than 10 meters, elevation positioning average error is less than 1.5 meters.

La Magneto-Impédance Géante (GMI) consiste en une forte variation de l’impédance d’un matériau ferromagnétique doux parcouru par un courant d’excitation alternatif haute fréquence lorsqu’il est soumis à un champ magnétique extérieur. Ce travail de thèse introduit de nouvelles techniques numériques et les pistes d’optimisation associées pour les capteurs GMI à haute sensibilité. L'originalité réside dans l'intégration d'un synthétiseur de fréquence et d'un récepteur entièrement numérique pilotés par un processeur de traitement de signal. Ce choix instrumental se justifie par le souhait de réduire le bruit de l’électronique de conditionnement qui limite le niveau de bruit équivalent en champ. Ce dernier caractérise le plus petit champ mesurable par le capteur. Le système de conditionnement conçu est associé à la configuration magnétique off-diagonal pour accroître la sensibilité intrinsèque de l’élément sensible. Cette configuration magnétique consiste en l’utilisation d’une bobine de détection autour du matériau ferromagnétique. Cette association permet en outre d’obtenir une caractéristique impaire de la réponse du capteur autour du champ nul, et par conséquent de pouvoir mettre en œuvre et d’utiliser le capteur sans avoir recours à une polarisation magnétique. Ce choix permet ainsi d’éliminer, ou au moins de minimiser les problématiques liées aux offsets des dispositifs GMI, tout en validant l’intérêt de cette configuration magnétique, notamment sur le choix du point de fonctionnement. Une modélisation des performances en bruit de toute la chaîne de mesure, incluant le système de conditionnement numérique, est réalisée. Une comparaison entre les niveaux de bruit équivalent en champ attendus par le modèle et mesurés est effectuée. Les résultats obtenus ont permis de dégager des lois générales d’optimisation des performances pour un capteur GMI numérique. Partant de ces pistes d’optimisation, un prototype de capteur complet et optimisé a été implémenté sur FPGA. Ce capteur affiche un niveau de bruit équivalent en champ de l’ordre de 1 pT/√Hz en zone de bruit blanc. En outre, ce travail permet de valider l’intérêt des techniques numériques dans la réalisation de dispositifs de mesure à haute sensibilité. / The Giant Magneto-Impedance (GMI) is a large change of the impedance of some soft ferromagnetic materials, supplied by an alternating high-frequency excitation current, when they are submitted to an external magnetic field. This thesis presents the design and performance of an original digital architecture for high-sensitivity GMI sensors. The core of the design is a Digital Signal Processor (DSP) which controls two other key elements: a Direct Digital Synthesizer (DDS) and a Software Defined Radio (SDR) or digital receiver. The choice of these digital concepts is justified by the will to reduce the conditioning electronics noise that limits the equivalent magnetic noise level. The latter characterizes the smallest measurable field by the sensor. The developed conditioning system is associated with the off-diagonal magnetic configuration in order to increase the intrinsic sensitivity of the sensitive element. This magnetic configuration consists of the use of an additional a pick-up coil wound around the ferromagnetic material. This association also makes it possible to obtain an asymmetrical characteristic (odd function) of the sensor response near the zero-field point and to consequently allow for sensor implementation and use without any bias magnetic field. Thus, this choice eliminates, or at least minimizes, the problems related to the offset cancelling of the GMI devices. Also, it validates the advantage of this magnetic configuration, especially the choice of the operating point. Modeling of the noise performance of the entire measurement chain, including the digital conditioning, is performed. A comparison between the expected and measured equivalent magnetic noise levels is then carried out. The results yield general optimization laws for a digital GMI sensor. Using these laws, an optimized prototype of a GMI sensor is designed and implemented on FPGA. An equivalent magnetic noise level in a white noise zone region of approximately 1 pT/√ Hz is obtained. Furthermore, this work also makes it possible to validate the interest of digital techniques in the realization of a high-sensitivity measuring devices.

Introduction: Type 2 diabetes continues to be one of the most common non-communicable diseases worldwide and complications due to type 2 diabetes, such as cardiovascular disease (CVD) can cause severe disability and even death. Despite advances in the development and validation of cardiovascular risk scores, those used in clinical practice perform inadequately for people with type 2 diabetes. Research has suggested that particular non-traditional biomarkers and novel omics data may provide additional value to risk scores over-and-above traditional predictors. Aims: To determine whether a small panel of non-traditional biomarkers improve prediction models based on a current cardiovascular risk score (QRISK2), either individually or in combination, in people with type 2 diabetes. Furthermore, to investigate a set of 228 metabolites and their associations with CVD, independent of well-established cardiovascular risk factors, in order to identify potential new predictors of CVD for future research. Methods: Analyses used the Edinburgh Type 2 Diabetes Study (ET2DS), a prospective cohort of 1066 men and women with type 2 diabetes aged 60-75 years at baseline. Participants were followed for eight years, during which time 205 had a cardiovascular event. Additionally, for omics analyses, four cohorts from the UCL-LSHTM-Edinburgh-Bristol (UCLEB) consortium were combined with the ET2DS. Across all studies, 1005 (44.73%) participants had CVD at baseline or experienced a cardiovascular event during follow-up. Results: In the ET2DS, higher levels of high sensitivity cardiac troponin (hs-cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) and lower levels of ankle brachial pressure index (ABI) were associated with incident cardiovascular events, independent of QRISK2 and pre-existing cardiovascular disease (odds ratios per one SD increase in biomarker 1.35 (95% CI: 1.13, 1.61), 1.23 (1.02, 1.49) and 0.86 (0.73, 1.00) respectively). The addition of each biomarker to a model including just QRISK2 variables improved the c-statistic, with the biggest increase for hs-cTnT (from 0.722 (0.681, 0.763) to 0.732 (0.690, 0.774)). When multiple biomarkers were considered in combination, the greatest c-statistic was found for a model which included ABI, hs-cTnT and gamma-glutamyl transpeptidase (0.740 (0.699, 0.781)). In the combined cohorts from the UCLEB consortium, a small number of high-density lipoprotein (HDL) particles were found to be significantly associated with CVD: concentration of medium HDL particles, total lipids in medium HDL, phospholipids in medium HDL and phospholipids in small HDL. These associations persisted after adjustment for a range of traditional cardiovascular risk factors including age, sex, blood pressure, smoking and HDL to total cholesterol ratio. Conclusions: In older people with type 2 diabetes, a range of non-traditional biomarkers increased predictive ability for cardiovascular events over-and-above the commonly used QRISK2 score, and a combination of biomarkers may provide the best improvement. Furthermore, a small number of novel omics biomarkers were identified which may further improve risk scores or provide better prediction than traditional lipid measurements such as HDL cholesterol.

La communauté de la chimie atmosphérique souffre d'un manque de mesures rapides, fiables résolues spatialement et temporellement pour un large éventail de molécules réactives (radicaux tels que NO2, OH, BrO, IO, etc). En raison de leur forte réactivité, ces molécules contrôlent largement la durée de vie et la concentration de nombreuses espèces clés dans l'atmosphère, et peuvent avoir un impact important sur le climat. Les concentrations de ces radicaux sont extrêmement faibles (ppbv ou moins) et très variable dans le temps et dans l'espace, ce qui impose un véritable défi lors de la détection. Dans la première partie de cette thèse, un spectromètre UV robuste, compacte et transportable est développé, exploitant la technique ML-CEAS pour mesurer à des niveaux très faibles (pptv et même en dessous) des molécules réactives d'importance atmosphérique, en particulier, les radicaux d'oxyde d'halogènes, afin de répondre aux besoins émergents. La technique ML-CEAS est basée sur le couplage d'un laser femtoseconde à blocage de modes à une cavité optique de haute finesse, qui agit comme un piège à photons pour augmenter l'interaction entre la lumière et l'échantillon de gaz intracavité. Cela permet d'améliorer fortement la sensibilité d'absorption. La limite de détection obtenue pour le radical IO est de 20 ppqv pour un temps d'acquisition de 5 minutes, ce qui est un résultat impressionnant. Dans la deuxième partie de cette thèse, une nouvelle technique spectroscopique est développée appelée effet Vernier, qui est également basé sur l'interaction entre un laser femtoseconde à blocage de mode et une cavité optique de haute finesse. Cette technique fournit une sensibilité de détection similaire à la technique ML-CEAS, mais l'avantage est que le nombre des éléments spectraux est donné par la finesse de la cavité optique et donc peut atteindre plusieurs dizaines de milliers. De plus, cette configuration simplifie le montage expérimental par la suppression du spectrographe qui est remplacé par une simple photodiode. Le temps d'acquisition d'un spectre peut être aussi réduit à moins d' 1 ms. / The atmospheric chemistry community suffers a lack of fast, reliable and space resolved measurements for a wide set of reactive molecules (e.g. radicals such as OH, NO3, BrO, IO, etc). Due to their high reactivity, these molecules largely control the lifetime and concentration of numerous key atmospheric species, and may have an important impact on the climate. The concentrations of such radicals are extremely low (ppbv or less) and highly variable in time and space, which imposes a real challenge during the detection. In the first part of this thesis, a compact, robust and transportable UV spectrometer is developed, exploiting the Mode-Locked Cavity Enhanced Absorption Spectroscopy (ML-CEAS) technique to measure pptv and sub-pptv levels of atmospherically important reactive molecules, in particular, halogen oxide radicals, to respond to the emerging needs. The ML-CEAS technique is based on coupling a Mode-Locked femtosecond laser to a high finesse optical cavity, which acts as a photon trap to increase the interaction between the light and the intracavity gas sample, which highly enhances the absorption sensitivity. The detection limit obtained for the IO radical is 20 ppqv (part per quadrillion), which is an impressive result. In the second part of this thesis, a new spectroscopic technique is developed, called Vernier effect, which is also based on the interaction between a mode-locked femtosecond laser with a high finesse optical cavity. This technique provides detection sensitivity similar to that of ML-CEAS technique, but the advantage is that the number of the spectral elements is given by the cavity finesse, so it can reach ten thousands, as well as this technique has a simple setup, where the spectrograph is replaced by a photodiode. Additionally, the time required to measure one output absorption spectrum can be less than 1 ms.

Les systèmes de navigation par satellite (GNSS) font partie de notre quotidien. On peut présentement les trouver dans un ensemble d’applications. Avec les nouveaux besoins, des nouveaux enjeux sont aussi apparus : le traitement du signal dans les environnements urbains est extrêmement complexe. Dans cette thèse, le traitement des signaux GNSS à faible puissance est abordé, en particulier dans la première phase du traitement, nommé acquisition de signal. Le premier axe de rechercheporte sur l’analyse et la compensation de l’effet Doppler dans l’acquisition. Le décalage Doppler perçu par l’utilisateur est un des paramètres principaux pour la configuration du module d’acquisition. Dans cette étude, des solutions sont proposées pour trouver le meilleur compromis sensibilité-complexité propre à l’acquisition. En deuxième axe, la caractérisation des détecteurs différentiels est abordée, en particulier la quantification de sa sensibilité. Pour l’acquisition des signaux faibles, après une première phase d’intégration cohérente, il faut passer par une intégration «postcohérente» (noncohérente ou différentielle.) L’analyse exécutée ici permet de meilleur identifier le meilleur choix entre les deux possibilités. Le troisième axe de recherche est consacré à la méthode de Détection Collective (CD), une innovation qui fait l’acquisition simultanée de tous les signaux visible par le récepteur. Plusieurs analyses sont réalisées incluant l’amélioration de la procédure de recherche de la CD, et l’hybridisation avec l’acquisition standard. Enfin on effectuel’analyse de la CD dans un contexte multi-constellation, en utilisant simultanément des vrais signaux GPS et Galileo. / Satellite navigation (GNSS) is a constant in our days. The number of applications that depend on it is already remarkable and is constantly increasing. With new applications, new challenges have also risen: much of the new demand for signals comes from urban areas where GNSS signal processing is highly complex. In this thesis the issue of weak GNSS signal processing is addressed, in particular at the first phase of the receiver processing, known as signal acquisition. The first axe of research pursued deals with the analysis and compensation of the Doppler effect in acquisition. The Doppler shift that is experienced by a user is one of the main design drivers for the acquisitionmodule and solutions are proposed to improve the sensitivity-complexity trade-off typical of the acquisition process. The second axe of research deals with the characterization of differential GNSS detectors. After a first step of coherent integration, transition to post coherent (noncoherent or differential) integration is required for acquiring weak signals. The quantification of the sensitivity of differential detectors was not found in literature and is the objective of this part of the research. Finally, the third axe of research is devoted to multi-constellation Collective Detection (CD). CD is an innovative approach for the simultaneous processing of all signals in view. Severalissues related to CD are addressed, including the improvement of the CD search process and the hybridization with standard acquisition. Finally, the application of this methodology in the context of a multi-constellation receiver is also addressed, by processing simultaneously real GPS and Galileo signals.

L’avènement du Génie électrique, il y a plus d’un siècle maintenant, s’est accompagné dès ses débuts, de recherche de matériaux ferromagnétiques performants pour la réalisation de l’élément central des dispositifs électromagnétiques, le circuit ou noyau magnétique. Ces matériaux, constitués initialement de fer, ont été très vite alliés au silicium, au cobalt et au nickel pour plusd’efficacité énergétique. Pour un dispositif donné, le choix d’un tel ou tel matériau passe souvent par un exercice de compromis vis-à-vis des besoins applicatifs (performances magnétiques, caractéristiques mécaniques et thermiques, etc., et bien sûr coût). La fréquence et la température de fonctionnement sont entre autres des paramètres importants. Parmi ces matériaux, les FeNi, bien qu’ils soient matures industriellement, voient toujours de nouveaux marchés s’ouvrirent à eux année après année grâce à l’attrait technique qu’ils exercent. Ce travail s'inscrit dans la continuité des recherches engagées à AMPERE sur les modèles comportementaux de matériaux magnétiques avec prise en compte des effets de la température. En effet, la recherche permanente de performances et de compacité ou intégration pour tous les dispositifs électromagnétiques soumet les circuits magnétiques à des contraintes physiques et en particulier thermiques de plus en plus sévères. Il est donc nécessaire de caractériser et modéliserprécisément les matériaux ferromagnétiques, et plus particulièrement les alliages FeNi, afin de les intégrer dans les outils de conception et d’optimisation de ces dispositifs. Pour cela, nous avons notamment dû mettre en oeuvre un dispositif expérimental adapté, et réaliser de nombreuses et longues expérimentations afin d’élaborer des modèles performants de comportement de ces matériaux. Ces modèles étudiés ou/et développés ont été ensuite testés sur une démonstrateur réel. Dans le cadre de cette thèse qui s’est déroulée en collaboration avec le Centre de Recherche du groupe APERAM, nous avons choisi une application particulièrement sensible en matière de sécurité des personnes « le système de protection différentielle » où le circuit magnétique (en alliage Fe–50%Ni ou Supra50) constitue une part très importante des performances et de la fiabilité. Enfin, de nouveaux alliages FeNi(Cr, Cu) à faible teneur en Ni (donc économiques) issus du Centre de Recherche d’APERAM ont été étudiés en vue de tester leur aptitude à remplacer le Supra50 dans ces systèmes. Le but est au final de proposer des alliages FeNi économiques aptesà la fabrication du circuit magnétique des relais de disjoncteurs différentiels à propre courant. / The advent of Electrical Engineering has been accompanied since its beginning, by the research of high performance ferromagnetic materials for the realization of the central element of electromagnetic devices, the magnetic core/circuit. These materials initially consisting of iron were alloyed with silicon, cobalt and nickel for more energy efficiency. For a given device, the material must be designed to meet the requirements of the application (magnetic performances, mechanical and thermal characteristics...and cost. The frequency and the operating temperature are, among others, important parameters to be taken into account. Among these materials, the FeNi alloys, although they are industrially mature, see new markets opened to them thanks to their certain specific characteristics and the innovations brought by the manufacturers of these materials. This work is a continuation of ongoing researches in AMPERE laboratory dealing with thebehavioral models of magnetic materials taking into account the effects of temperature. Indeed, there is a trend in a growing number of electromagnetic devices to require high performance and compactness or integration. Thus, in this context, the magnetic circuits are subjected to physical and thermal stresses that are becoming more and more stringent. It is therefore necessary to resort to the experimental characterization and modeling of the behavior of ferromagnetic materials, particularly the FeNi alloys, in order to integrate them into the design and optimization tools of these devices. To do so, we have implemented an appropriate experimental bench, andachieve many and long experiments to develop advanced behavioral models of these materials. These models were then tested on a particularly sensitive application in the field of safety of persons, the differential protection system where the magnetic circuit (of Fe-50% Ni or Supra50) is a very important part of performance and reliability. Finally, new low Ni content FeNi (Cr, Cu) alloys provided by Aperam Research Center in Imphy, were studied in order to test their ability to replace the usual Supra50 alloy in these systems. The final aim is to propose new economic FeNi alloys suitable for the manufacture of the magnetic circuit of industrial ground fault circuit-breaker relay.

Control and analysis of protein aggregation is an increasing challenge to biopharmaceutical research and development. Therefore it is important to understand the interactions, causes and analysis of particles in order to control protein aggregation to enable successful biopharmaceutical formulations. This work investigates the role of different non-ionic surfactants on protein conformational stability, as assessed by HSDSC, and on protein size stability as assessed by Dynamic Light Scattering (DLS), HIAC and MFI. BSA and IgG2 were used as model proteins. Thermal unfolding experiments indicated a very weak surfactant-immunoglobulin IgG2 interaction, compared to much stronger interactions for the BSA surfactant systems. The DLS results showed that BSA and IgG2 with different surfactants and concentration produced different levels of particle size growth. The heat treatment and aging of samples in the presence of Tween 20, Tween 80, Brij 35 and Pluronic F-68 surfactants led to an increase in the populations of larger particles for BSA samples, whereas IgG2 systems did not notably aggregate under storage conditions MFI was shown to be more sensitive than HIAC technique for measuring sub-visible particles in protein surfactant systems. Heat treatment and storage stress showed a significant effect on BSA and IgG2 protein sub-visible particle size stability. This work has demonstrated that both proteins with different Tween 20, Tween 80, Brij 35 and Pluronic F-68 concentrations, have different level of conformational and size stability. Also aging samples and heating stress bears the potential to generate particles, but this depends on surfactant type. Poor predictive correlations between the analytical methods were determined.

Endotelio funkcijos sutrikimas (disfunkcija) - būklė, apibūdinama padidėjusia adhezijos molekulių ekspresija, padidėjusia prouždegiminių veiksnių ir protrombotinių faktorių sinteze bei sutrikusia kraujagyslių tono reguliacija - yra mirties dėl kardiovaskulinės patologijos, miokardo infarkto bei poreikio revaskuliarizacijos procedūroms išsivystymo rizikos veiksnys. Darbo tikslas buvo nustatyti endotelio pažeidimą atspindinčių žymenų, hs-CRP, sVCAM-1 ir sICAM-1 reikšmę, nuspėjant kardiovaskulines komplikacijas po aortos vainikinių jungčių suformavimo operacijos, atliktos dirbtinės kraujo apytakos sąlygomis. Nustatėme, kad didesnės priešoperacinės hs-CRP ir sVCAM-1 koncentracijos buvo nepriklausomi didesnės kardiovaskulinių komplikacijų po aortos vainikinių jungčių suformavimo operacijų rizikos žymenys. Po aortos vainikinių jungčių suformavimo operacijos nustatyta reikšmingai didesnė hs-CRP, sVCAM-1 ir sICAM-1 koncentracija, palyginus su priešoperaciniu koncentracijos lygiu. Patikimos žymenų koreliacijos su aortos užspaudimo, dirbtinės kraujo apytakos bei operacijos trukme neradome. Pacientams po aortos vainikinių jungčių suformavimo operacijos koreliacijos tarp pooperacinio sICAM-1, sVCAM-1 bei hs-CRP koncentracijos lygio ir kardiovaskulinių komplikacijų išsivystymo rizikos nebuvo nenustatyta. / The endothelial cell damage/dysfunction is associated with increased expression of adhesion molecules, synthesis of proinflammatory, prothrombotic factors and abnormal modulation of vascular tone. A growing body of evidence suggests that endothelial dysfunction is associated with future cardiovascular events including cardiac death, myocardial infarction and the need for revascularization procedures. The aim of the study was to evaluate the impact of markers of endothelial damage as predictors of cardiovascular events after on-pump coronary artery bypass grafting surgery. We found that higher concentrations preoperatively of hs-CRP and sVCAM-1 were independent markers for higher risk of cardiovascular events after coronary artery bypass grafting surgery. Concentration of hs-CRP, sVCAM-1 and sICAM-1 increased significantly after on-pump coronary artery bypass grafting surgery compared to preoperative level. However correlation between the duration of aortic cross-clamp, cardiopulmonary bypass or surgery and markers of endothelial damage was not found. Correlation between postoperative concentration of hs-CRP, sVCAM-1 and sICAM-1 and risk for cardiovascular events after coronary artery bypass grafting surgery was not found.

Endotelio funkcijos sutrikimas (disfunkcija) - būklė, apibūdinama padidėjusia adhezijos molekulių ekspresija, padidėjusia prouždegiminių veiksnių ir protrombotinių faktorių sinteze bei sutrikusia kraujagyslių tono reguliacija - yra mirties dėl kardiovaskulinės patologijos, miokardo infarkto bei poreikio revaskuliarizacijos procedūroms išsivystymo rizikos veiksnys. Darbo tikslas buvo nustatyti endotelio pažeidimą atspindinčių žymenų, hs-CRP, sVCAM-1 ir sICAM-1 reikšmę, nuspėjant kardiovaskulines komplikacijas po aortos vainikinių jungčių suformavimo operacijos, atliktos dirbtinės kraujo apytakos sąlygomis. Nustatėme, kad didesnės priešoperacinės hs-CRP ir sVCAM-1 koncentracijos buvo nepriklausomi didesnės kardiovaskulinių komplikacijų po aortos vainikinių jungčių suformavimo operacijų rizikos žymenys. Po aortos vainikinių jungčių suformavimo operacijos nustatyta reikšmingai didesnė hs-CRP, sVCAM-1 ir sICAM-1 koncentracija, palyginus su priešoperaciniu koncentracijos lygiu. Patikimos žymenų koreliacijos su aortos užspaudimo, dirbtinės kraujo apytakos bei operacijos trukme neradome. Pacientams po aortos vainikinių jungčių suformavimo operacijos koreliacijos tarp pooperacinio sICAM-1, sVCAM-1 bei hs-CRP koncentracijos lygio ir kardiovaskulinių komplikacijų išsivystymo rizikos nebuvo nenustatyta. / The endothelial cell damage/dysfunction is associated with increased expression of adhesion molecules, synthesis of proinflammatory, prothrombotic factors and abnormal modulation of vascular tone. A growing body of evidence suggests that endothelial dysfunction is associated with future cardiovascular events including cardiac death, myocardial infarction and the need for revascularization procedures. The aim of the study was to evaluate the impact of markers of endothelial damage as predictors of cardiovascular events after on-pump coronary artery bypass grafting surgery. We found that higher concentrations preoperatively of hs-CRP and sVCAM-1 were independent markers for higher risk of cardiovascular events after coronary artery bypass grafting surgery. Concentration of hs-CRP, sVCAM-1 and sICAM-1 increased significantly after on-pump coronary artery bypass grafting surgery compared to preoperative level. However correlation between the duration of aortic cross-clamp, cardiopulmonary bypass or surgery and markers of endothelial damage was not found. Correlation between postoperative concentration of hs-CRP, sVCAM-1 and sICAM-1 and risk for cardiovascular events after coronary artery bypass grafting surgery was not found.