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Abstract: Background/Objectives: Sodium glucose co-transporter 2 inhibitors (SGLT2is) improve outcomes in heart failure; however, data in left ventricular non-compaction cardiomyopathy (LVNC) patients are limited. We sought to analyze the clinical effects of the SGLT2is dapagliflozin and empagliflozin in patients with LVNC. Methods: Thirty consecutive LVNC patients diagnosed by CMR were prospectively enrolled. Clinical, biochemical and echocardiography data were obtained at the initiation of the SGLT2is and at the 12-month follow-up. All patients were on stable guideline-directed medical therapy. A response to SGLT2i therapy was defined as an improvement in LVEF ≥ 5% at 12 months. Results: Of the 30 enrolled patients, 25 were male, with a mean age of 49 ± 16 years and few comorbidities. Dapagliflozin 10 mg was prescribed to 23 patients and empagliflozin 10 mg to 7 patients. Five patients experiened an adverse event during follow-up (one sudden cardiac death; four heart transplantations or LVAD implantations). During follow-up, significant improvements were observed in LVEF (32.1 ± 6.9% vs. 43.5 ± 9.7%; p = 0.003), LVOT VTI (14.8 ± 6.5 cm vs. 17.6 ± 3.3 cm; p = 0.008), E/e′ (14.8 ± 4.7 vs. 10.0 ± 4.1; p < 0.001), and TAPSE (2.0 ± 0.4 cm vs. 2.3 ± 0.4 cm; p = 0.012). NT-proBNP levels decreased significantly (2025 ± 2198 pg/mL vs. 582 ± 803 pg/mL; p = 0.005). Eighteen patients responded favorably to SGLT2i therapy (Group A), whereas seven showed no significant LVEF improvement (Group B). The groups did not differ significantly in age, sex, baseline creatinine, or bilirubin. Compared to Group B, Group A had a smaller baseline LV end-diastolic diameter (6.3 ± 0.8 cm vs. 7.1 ± 0.9 cm; p = 0.025) and lower NT-proBNP levels (1720 ± 1662 pg/mL vs. 4527 ± 4397 pg/mL; p = 0.02). Conclusions: In patients with LVNC, SGLT2i therapy is associated with significant reverse remodeling and functional improvement. Benefits may be greater in those with less advanced disease.
Keywords: non-compaction cardiomyopathy, guideline-directed heart failure medical therapy, myocardial recovery
Published in DiRROS: 15.12.2025; Views: 220; Downloads: 77
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Abstract: Pipe bends disrupt the flow, resulting in an asymmetric velocity field across the pipe diameter (D). We examined the recovery length required for the flow to return to a symmetric velocity profile downstream of a sharp elbow. The wall-resolved Large Eddy Simulation (LES) approach was applied to reproduce turbulent fluid flow at Reynolds numbers (�� ) of 5600 and 10,000. An additional case in the transitional laminar-turbulent-laminar regime was analyzed at ��=1400 . This analysis explored the behavior of the Dean vortices downstream of the elbow and revealed that, in turbulent cases, these vortices reverse their vorticity direction in the region between 8 D and 10 D. However, they eventually decay in structure as far as 25 D from the elbow. Flow asymmetry was analyzed in a 100 D long pipe section downstream of the elbow using four different criteria: wall shear stress (WSS), streamwise velocity, its fluctuations, and vorticity fields. This study found that in turbulent flows, the distance required for flow recovery is a few tens of D and decreases with increasing ��. However, in the transitional case, the flow separation within the elbow induces instabilities that gradually diminish downstream, and flow asymmetry persists even longer than the 100 D length of our outlet pipe section. WSS proved sensitive for detecting asymmetry near walls, whereas flow profiles better revealed bulk asymmetry. It was also shown that asymmetry indicators derived from velocity fluctuations and vorticity were less sensitive than those obtained from streamwise velocity.
Keywords: cevno koleno, flow asymmetry, pipe elbows, secondary flow, flow separation, turbulent flow, recovery length, Large Eddy Simulation
Published in DiRROS: 27.03.2025; Views: 644; Downloads: 366
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Abstract: Background. PET/CT imaging is widely used in oncology and provides both metabolic and anatomic information. Because of the relatively poor spatial resolution of PET, the detection of small lesions is limited. The low spatial resolution introduces the partial-volume effect (PVE) which negatively affects images both qualitatively and quantitatively. The aim of the study was to investigate the effect of small-voxel (2 mm in-line pixel size) vs. standard-voxel (4 mm in-line pixel size) reconstruction on lesion detection and image quality in a range of activity ratios. Materials and methods. The National Electrical Manufacturers Association (NEMA) body phantom and the Micro Hollow-Sphere phantom spheres were filled with a solution of [18F]fluorodeoxyglucose ([18F]FDG) in sphere-to-background ratios of 2:1, 3:1, 4:1 and 8:1. In all images reconstructed with 2 mm and 4 mm in-line pixel size the visual lesion delineation, contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) were evaluated. Results. For smaller (≤ 13 mm) phantom spheres, significantly higher CRC and CNR using small-voxel reconstructions were found, also improving visual lesion delineation. CRC did not differ significantly for larger (≥ 17 mm) spheres using 2 mm and 4 mm in-line pixel size, but CNR was significantly lower; however, lower CNR did not affect visual lesion delineation. Conclusions. Small-voxel reconstruction consistently improves precise small lesion delineation, lesion contrast and image quality.
Keywords: PET/CT, voxel size, contrast recovery coefficient, contrast-to-noise ratio
Published in DiRROS: 24.07.2024; Views: 936; Downloads: 598
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Abstract: For many years the properties of bitumen have been determined based on mechanical tests as needle penetration, Ring&Ball and Fraass fracture temperature. For elastomer (styrene-butadiene-styrene) polymer modified bitumens these tests are not sufficient to show the important differences in bitumens. Elastic recovery and cohesion provide better insight, but rheological properties cannot be adequately described with conventional test. The requirements of the polymer modified bitumens (PmB) in Europe were defined in EN14023 in 2010 [1]. Since then several new tests were introduced in the research field and their procedures improved. In the European Standards Committee (CEN) TC 336, there is on-going work to develop performance related specifications. New laboratory test methods from American standards were adapted and transformed into EN standards (bitumen laboratory aging methods and rheological tests). These test methods are not yet employed in the cur-rent PmB European standard, however, the draft prEN 14023, April 2020 [2] suggests these new tests. In the recent years at ZAG Laboratory for asphalts and bitumen-based products long-term aging of bitumen by pressure aging vessel (PAV) and rheological tests were introduced. Traditional bitumen test methods are performed together with new rheological testse.g. Dynamic Shear Rheometer (DSR) testing, to characterize complex modulus and phase angle, and Multiple Stress Creep Recovery Test (MSCRT) in order to develop a preliminary data base on PmB’s, which are frequently used in Slovenia. The paper presents the current requirements for PmB’s in Slovenia and test results on PmB 45/80-65, original, laboratory aged and extracted from produced asphalt mixtures.
Keywords: polymer modified bitumen, recovered bitumen, laboratory ageing, dynamic shear rheometer, multiple stress creep recovery test
Published in DiRROS: 28.02.2024; Views: 1282; Downloads: 1056
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Abstract: Innovation in the circular economy (CE) and the deployment of effective circular business models (CBM) have attracted significant attention in times of growing natural resource scarcity. Despite this widespread interest, significant challenges remain between theoretical innovations and effective CBM implementation in any industrial sector where companies pursue cost-saving opportunities through waste valorisation strategies. Since current methods mislead in terms of the real limitations to designing feasible novel products and services under a circular economy, this study proposes exploring determinants underpinning the organisational resilience of CBMs under a resource efficiency strategy through three case studies. As a result of a co-creation process, the implementation of a CBM framework was built upon empirical data and, thence, a phase-based implementation guide was laid out to assist companies in designing and implementing innovative CBM dealing with the complexity of innovative waste valorisation strategies between the PPI and construction sectors. Relevant findings on managerial and policy recommendations encountered along the demo stage are provided in this paper favouring an effective implementation of CE strategies: the role of technological and non-technological aspects within the CBM, the perspective of the ecosystem and its value proposition, and specific guidelines for the different phases of CBM life cycle.
Keywords: circular business models (CBMs), resource recovery, waste valorisation, strategic management, pulp and paper industry (PPI), construction sector
Published in DiRROS: 13.12.2023; Views: 1275; Downloads: 783
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