Anti‐atherosclerotic effect of the angiotensin 1–7 mimetic AVE0991 is mediated by inhibition of perivascular and plaque inflammation in early atherosclerosis

Background and Purpose: Inflammation plays a key role in atherosclerosis. A protective role of angiotensin-(1-7) in vascular pathologies opened a possibility for therapeutic use of small molecule non-peptide Ang-(1-7) mimetics, such as AVE0991. The mechanisms of these vaso-protective effects of a Mas receptor agonist, AVE0991, remain unclear. Experimental approach: We investigated the effects of AVE0991 on the spontaneous atherosclerosis in ApoE-/- mice, in the context of vascular inflammation and plaque stability. Key Results: AVE0991 has significant anti-atherosclerotic properties in ApoE-/- mice and increases plaque stability, by reducing plaque macrophage content, without effects on collagen. Using descending aorta of chow fed ApoE-/- mice, before significant atherosclerotic plaque develops, we gained insight to early events in atherosclerosis. Interestingly, perivascular adipose tissue (pVAT) and adventitial infiltration with macrophages and T cells precedes atherosclerotic plaque or the impairment of endothelium-dependent NO bioavailability as a measure of endothelial function. AVE0991 inhibited perivascular inflammation, through the reduction of chemokine expression in pVAT, as well as through direct actions on monocytes/macrophages inhibiting their activation, characterized by IL-1β, TNF-α, MCP-1 and CXCL10 and differentiation to M1 phenotype. Pre-treatment with AVE0991 inhibited migration of THP-1 monocytes towards supernatants of activated adipocytes (SW872). Mas receptors were expressed in pVAT and in THP-1 cells in vitro and anti-inflammatory effects of AVE0991 were partially Mas dependent. Conclusions & implications: Selective Mas receptor agonist AVE0991 possesses anti-atherosclerotic and anti-inflammatory properties, affecting monocyte/macrophage differentiation and recruitment to perivascular space at early stages of atherosclerosis in ApoE-/- mice

The novel photoresponsive oligomers containing azo derivatives of sulfamerazine for spontaneous surface relief grating inscription

In this work, a novel photoresponsive materials has been successfully developed. We have synthesized the series of azopolymers containing derivatives of sulfamerazine and studied their photochromic properties. The polymers were obtained from methacrylate azomonomers, butyl methacrylate and isobornyl methacrylate by radical polymerization. Spectral properties and photoisomerization kinetic constants were determined for thin transparent films, using UV-Vis spectroscopy. The maximum absorption of the films was observed at 432-440 nm. The obtained materials showed ability to reversible trans-cis photoisomerization. Reversibility of the process was confirmed during ellipsometric measurements. The change of the real part of the complex refractive index induced by laser irradiation was between 0.010 and 0.053. Additionally, some properties of described polymers and azobenzene derivatives were calculated and were utilized in order to better understand the differences in the photochromic behaviour of the new materials. Moreover, we determined the suitability of the obtained azopolymers for spontaneous surface relief grating inscription. Spontaneous surface relief grating recording on the thin azopolymer films was carried out using set-up with one laser beam. The spontaneous SRG was successfully recorded in all investigated polymers

Association of carotid atherosclerosis and peripheral artery disease in patients with type 2 diabetes: risk factors and biomarkers

BACKGROUND: Carotid atherosclerosis (CA) and lower extremity peripheral artery disease (PAD) is a common and potentially life-threatening comorbidity in diabetes.AIM: to determine risk factors and biomarkers of the association of CA and PAD in patients with type 2 diabetes.MATERIALS AND METHODS: A single-center cross-sectional comparative study was carried out. Three hundred ninety one patients with type 2 diabetes were included. Duplex ultrasound of carotid and low limb arteries, screening/monitoring of diabetic complications and associated diseases, and assessment of glycemic control, biochemical and coagulation parameters were performed. Factors involved in vascular wall remodeling, including calponin-1, relaxin, L-citrulline, matrix metalloproteinase-2 and -3, were measured in blood serum by ELISA.RESULTS: The signs of CA and PAD were observed in 330 and 187 patients respectively. In 178 patients, both CA and PAD were revealed. The risk of combined involvement of carotid and lower extremity arteries was higher in patients with diabetic retinopathy (OR=2.57, p<0.001), chronic kidney disease (OR=4.48, p<0.001), history of myocardial infarction (OR=5.09, p<0.001), coronary revascularization (OR=4.31, p<0.001) or cerebrovascular accident (OR=3.07, p<0.001). In ROC-analysis, age ≥65.5 years (OR=3.43, p<0.001), waist-to-hip ratio ≥0.967 (OR=3.01, p=0.001), diabetes duration ≥12.5 years (OR=3.7, p<0.001), duration of insulin therapy ≥4.5 years (OR=3.05, p<0.001), duration of arterial hypertension ≥16.5 years (OR=1.98, p=0.002), serum L-citrulline ≥68 µmol/l (OR=3.82, p=0.003), and mean amplitude of glucose excursions ≥3.72 mmol/l (OR=1.79, p=0.006) were the risk factors for atherosclerosis of two vascular beds. In multivariate logistic regression analysis, age, diabetes duration and waist-to-hip ratio were independent risk factors for association of CA and PAD (p=0.005, p=0.0003, and p=0.004 respectively).CONCLUSION: In subjects with type 2 diabetes, carotid and lower extremity atherosclerotic disease is associated with age, diabetes duration, abdominal obesity, microvascular and macrovascular complications, glucose variability, and high serum levels of L-citrulline

Destruction of chemical warfare surrogates using a portable atmospheric pressure plasma jet

Today’s reality is connected with mitigation of threats from the new chemical and biological warfare agents. A novel investigation of cold plasmas in contact with liquids presented in this paper demonstrated that the chemically reactive environment produced by atmospheric pressure plasma jet (APPJ) is potentially capable of rapid destruction of chemical warfare agents in a broad spectrum. The decontamination of three different chemical warfare agent surrogates dissolved in liquid is investigated by using an easily transportable APPJ. The jet is powered by a kHz signal source connected to a low-voltage DC source and with He as working gas. The detailed investigation of electrical properties is performed for various plasmas at different distances from the sample. The measurements of plasma properties in situ are supported by the optical spectrometry measurements, whereas the high performance liquid chromatography measurements before and after the treatment of aqueous solutions of Malathion, Fenitrothion and Dimethyl Methylphosphonate. These solutions are used to evaluate destruction and its efficiency for specific neural agent simulants. The particular removal rates are found to be from 56% up to 96% during 10 min treatment. The data obtained provide basis to evaluate APPJ’s efficiency at different operating conditions. The presented results are promising and could be improved with different operating conditions and optimization of the decontamination process

Energetic aspects of needle bearings work performance

W pracy przedstawiono analizę równania zużycia w ujęciu energetycznym na przykładzie łożyskowania igiełkowego wału głównego skrzyni biegów ciągnika rolniczego. Przeanalizowano wpływ zewnętrznych oddziaływań na charak- ter zużycia w funkcji czasu w węźle tarciowym. Właściwości, którymi charakteryzują się zdeformowane obszary powierzchni tarcia mają zasadniczy wpływ na trwałość elementów pary tarcia. Konieczny jest prawidłowy wybór materiałów na ele- menty tarciowe, charakteryzujące się strukturą o największej odporności na pękanie pod wpływem eksploatacyjnych oddziaływań zewnętrznych. Oznacza to, że materiałoznawstwo tribotechniki powinno być rozpatrywane na bazie analizy mikrostruktur.The paper presents the analysis of wear equation in energetic approach exemplified by a needle bearing of tractors third motion shaft. The authors analysed the influence of external factors on the type of wear in the function of time in frictional contact. Properties which are typical of deformed sections of friction surface have essential influence on the durability of the elements of friction couple. It is crucial to make the right choice of materials for friction elements which ought to have structure of the largest resistance to cracking as a result of external exploitation influences. This means that the material science of tribotechnology should be considered on the basis of micro- structure analyses

Kinematics friction pair for example needle bearings

Niniejszy artykuł dotyczy zjawisk zachodzących w łożyskowaniu igiełkowym. Tarcie generujące moment oporu pracy węzła ciernego jest głównym czynnikiem mającym wpływ na jego zużycie. W łożysku igiełkowym mamy do czynienia z dwoma wiodącymi rodzajami tarcia: tarciem tocznym i tarciem poślizgu, i te właśnie procesy są głównym przedmiotem badań. W pracy przedstawiono wyniki z rejestracji i analizy ruchu wszystkich elementów tocznych w łożyskowaniu. Doświadczenia przeprowadzono na stanowisku badawczym możliwie dokładnie oddającym warunki realnej pracy łożyska. Odpowiednio przygotowana metodyka badań pozwala na pomiar i analizę oporu ruchu łożyska, określenie strefy czynnego przenoszenia obciążenia i wyznaczenie współczynników tarcia.The present study concerns certain phenomena that take place in the needle roller bearing. The friction that generates the anti-torque of a friction pair is the major factor that influences the needle bearing’s wear. In the needle bearing there occur two predominant types of friction: the rolling friction and the sliding friction, and both are subject to examination. The study presents recordings and analysis of the movements of all needle bearing’s rolling elements. The examination was carried out on a special examination stand that precisely emulates the real conditions of the needle bearing’s work. Carefully prepared examination methods enable recording and analyzing frictions in the bearing, estimating a sphere within which the load is shifted, and calculating the coefficient of friction

The stand for modelling the process of friction in the needle bearing

W pracy przedstawiono stanowisko przeznaczone do badania procesu tarcia i zużycia w łożyskowaniu igiełkowym. Prezentowane stanowisko pozwala zarejestrować prędkości obrotowe wałka i igiełek, moment tarcia oraz wydzielające się ciepło. Zmiana obciążenia, środowiska pracy oraz prędkości obrotowej w połączeniu ze zmienną geometrią elementów współpracujących w węźle tarciowym, pozwala na zbadanie wpływu tych parametrów na moment tarcia i zużycie. Obecnie nie istnieje powszechnie funkcjonująca metoda umożliwiająca określenie tarcia poślizgu w łożyskowaniu igiełkowym - zatem budowa stanowiska jest zasadna.The article introduces a stand designed for examining the process of friction and wear in the needle bearing. The device enables us to record the rotational speed of the shaft neck and needle rollers, the moment of friction and the heat emitted. Alterations in the load, the working environment and the rotational speed combined with changing geometry of cooperating elements in the friction pair make it possible to estimate the influence of these parameters on the moment of friction and the degree of wear. At present there is no commonly accepted method of measuring the needle spin in the needle bearing, which means that constructing the stand is justifiable