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A fully 3D unsteady Computational Fluid Dynamics (CFD) approach coupled with heterogeneous reaction chemistry is presented in order to study the behavior of a single square channel as part of a Lean [Formula: see text] Traps. The reliability of the numerical tool has been validated against literature data considering only active BaO site. Even though the input/output performance of such catalyst has been well known, here the spatial distribution within a single channel is investigated in details. The square channel geometry influences the flow field and the catalyst performance being the flow velocity distribution on the cross section non homogeneous. The mutual interaction between the flow and the active catalyst walls influences the spatial distribution of the volumetric species. Low velocity regions near the square corners and transversal secondary flows are shown in several cross-sections along the streamwise direction at different instants. The results shed light on the three-dimensional characteristic of both the flow field and species distribution within a single square channel of the catalyst with respect to 0-1D approaches.

Obstructive sleep apnea syndrome (OSAS) in children can induce endothelial dysfunction, a well-known early marker of atherosclerosis. The study aimed to evaluate a link among endothelial function (measured by flow-mediated vasodilation (FMD)), obesity (evaluated by body mass index (BMI)), and sleep disordered breathing (SDB), assessed with apnoea/hypopnoea index (AHI), in a paediatric population. We demonstrated that our little OSAS patients showed an impaired endothelial function as compared to controls. In particular, the higher the AHI, the worst the FMD values and thus the endothelial function. Although the population sample is small, this study demonstrated that OSAS could impair endothelial function and worsen cardiovascular risk profile since childhood.

Purpose: According to the literature, estradiol has a direct vasodilator action by means of endothelium-derived relaxing factor synthesis. The present study aims to evaluate the acute hemodynamic effects of intranasal 17-β-estradiol on cerebral and lower limb arterial circulation in postmenopausal women., Methods: Sixteen healthy women in natural menopause (mean age: 54 ± 3 years) were investigated for at least 6 months, each receiving 300 µg of intranasal 17-β-estradiol. We evaluated the heart rate, systolic/diastolic blood pressure, peak systolic velocity, end-diastolic velocity, and velocity-time integral (VTI) at the level of internal carotid and posterior tibial arteries, before and after 30, 60, and 180 minutes of drug administration., Results: After intranasal 17-β-estradiol administration, the internal carotid artery VTI showed statistically significant (P < .05) variations at all the time intervals after administration of the drug (30, 60, and 180 minutes) when compared with "time zero" (T0, ie, the speed recorded at baseline before drug administration). No significant variation was found at the posterior tibial artery. The systolic/diastolic blood pressure and heart rate did not significantly differ before and after drug administration., Conclusions: The administration of a single intranasal dose of 17-β-estradiol in healthy postmenopausal women increased cerebral perfusions, whereas the effect on peripheral circulation was much more limited.

Aim: To evaluate the influence of selected maternal and neonatal characteristics on aorta walls in term, appropriately grown-for-gestational age newborns., Methods: Age, parity, previous abortions, weight, height, body mass index before and after delivery, smoking, and history of hypertension, of diabetes, of cardiovascular diseases, and of dyslipidemia were all assessed in seventy mothers. They delivered 34 males and 36 females healthy term newborns who underwent ultrasound evaluation of the anteroposterior infrarenal abdominal aorta diameter (APAO), biochemical profile (glucose, insulin, total cholesterol, HDL and LDL cholesterol, triglycerides, fibrinogen, and D-dimers homeostasis model assessment [HOMAIR]index), and biometric parameters., Results: APAO was related to newborn length (r = +0.36; P = 0.001), head circumference (r = +0.37; P = 0.001), gestational age (r = +0.40, P = 0.0005), HOMA index (r = +0.24; P = 0.04), and D-dimers (r = +0.33, P = 0.004). Smoke influenced APAO values (odds ratio: 1.80; confidence interval 95%: 1.05-3.30), as well as diabetes during pregnancy (r = +0.42, P = 0.0002). Maternal height influenced neonatal APAO (r = +0.47, P = 0.00003). Multiple regression analysis outlined neonatal D-dimers as still significantly related to neonatal APAO values., Conclusions: Many maternal and neonatal characteristics could influence aorta structures. Neonatal D-dimers are independently related to APAO.

Objective: To evaluate cardiovascular risk factors and pre-clinical atherosclerosis in subjects affected by idiopathic sudden sensorineural hearing loss (ISSHL)., Methods: In this study, 29 ISSHL patients and 29 healthy controls were evaluated. All of the patients underwent a complete audiovestibular and clinical evaluation. Carotid intima-media thickness (C-IMT) and flow-mediated dilation (FMD) of the brachial artery were assessed as early markers of atherosclerosis., Results: Our results showed that FMD was significantly lower in the ISSHL patients than in the controls (5.6 ± 1.6% vs. 7.7 ± 3.7%, p < 0.01). Moreover, the total cholesterol and low density lipoprotein cholesterol were significantly higher in the ISSHL patients than in the controls (p < 0.05). The two groups did not differ with regards to C-IMT and other cardiovascular risk factors. Vestibular involvement was shown to be associated with lower FMD values (4.1 ± 1.7% vs. 5.8 ± 1.5%, p < 0.05). No relationship was found between C-IMT and vestibular involvement. Finally, multiple logistic regression highlighted the finding that only FMD values seemed to predispose individuals to developing ISSHL (p = 0.03, OR: 1.4)., Conclusions: ISSHL seemed to be associated with vascular endothelial dysfunction and an increased cardiovascular risk, which supports the hypothesis of a vascular aetiology for this disease., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Aim: The study aim was to evaluate the acute hemodynamic effects of intranasal 17-beta-estradiol on ophthalmic arterial circulation in postmenopausal women., Methods: Twenty-one healthy women in natural menopause for at least 6 months (mean age: 53.2± 2.9 years) were investigated. Each patient received 300 µg intranasal 17-beta-estradiol. We evaluated the heart rate, systolic and diastolic blood pressure, ophthalmic artery velocity at systolic and diastolic peak and its flow curve integral (FCI) before and 30, 60 and 180 minutes after the administration of the drug., Results: At all time points, the ophthalmic artery FCI showed statistically significant variations (p<0.001) of velocity (cm/sec) compared to T0 (speed recorded at baseline before drug administration). Moreover, systolic blood pressure, diastolic blood pressure and heart rate did not significantly differ each other after drug administration., Conclusions: Administration of a single dose of intranasal 17-beta-estradiol to healthy postmenopausal women increases ophthalmic artery perfusion.