Experimental and numerical study of pressure drop in pipes packed with large particles

This study investigates the pressure drop in horizontal pipes packed with large particles that result in small pipe-to-particle diameter ratio both experimentally and numerically. Two horizontal pipes of 0.1905 and 0.0254 m ID filled with cylindrical or spherical particles are used to collect the experimental data for single and two-phase flows. The porosity has same value for both pipes when they packed with cylindrical particles which is 0.75, however has different values when packed with spherical particles, 0.7 for the large pipe and 0.57 for the small pipe. The Roe-type Riemann solver proposed by Santim and Rosa Int J Numer Methods Fluids 80 (9), 536–568, [36] which uses the Drift-Flux model is modified aiming to predict the pressure drop in porous media through the implementation of a new source term in the system of equations. Empirical models available in the literature are used to calculate the single and two-phase flows pressure drop. The motivation is to verify the solver capability to reproduce the two-phase flow pressure drop in porous media and to compare some empirical models existing in the literature against the experimental data provided modifying some empirical coefficients when necessary.</p

Effects of abciximab on key pattern of human coronary restenosis in vitro: impact of the SI/MPL-ratio

BACKGROUND: The significant reduction of angiographic restenosis rates in the ISAR-SWEET study (intracoronary stenting and antithrombotic regimen: is abciximab a superior way to eliminate elevated thrombotic risk in diabetes) raises the question of whether abciximab acts on clopidogrel-independent mechanisms in suppressing neointimal hyperplasia. The current study investigates the direct effect of abciximab on ICAM-1 expression, migration and proliferation. METHODS: ICAM-1: Part I of the study investigates in cytoflow studies the effect of abciximab (0.0002, 0.002, 0.02, 0.2, 2.0, and 20.0 μg/ml) on TNF-α induced expression of intercellular adhesion molecule 1 (ICAM-1). Migration: Part II of the study explored the effect of abciximab (0.0002, 0.002, 0.02, 0.2, 2.0, and 20.0 μg/ml) on migration of HCMSMC over a period of 24 h. Proliferation: Part III of the study investigated the effect of abciximab (0.0002, 0.002, 0.02, 0.2, 2.0, and 20.0 μg/ml) on proliferation of HUVEC, HCAEC, and HCMSMC after an incubation period of 5 days. RESULTS: ICAM-1: In human venous endothelial cells (HUVEC), human coronary endothelial cells (HCAEC) and human coronary medial smooth muscle cells (HCMSMC) no inhibitory or stimulatory effect on expression of ICAM-1 was detected. Migration: After incubation of HCMSMC with abciximab in concentrations of 0.0002 – 2 μg/ml a stimulatory effect on cell migration was detected, statistical significance was achieved after incubation with 0.002 μg/ml (p < 0.05), 0.002 μg/ml (p < 0.001), and 0.2 μg/ml (p < 0.05). Proliferation: Small but statistically significant antiproliferative effects of abciximab were detected after incubation of HUVEC (0.02 and 2.0 μg/ml; p = 0.01 and p < 0.01), HCAEC (2.0 and 20.0 μg/ml; p < 0.05 and p < 0,01), and HCMSMC (2.0 and 20.0 μg/ml; p < 0.05 and p < 0.05). The significant inhibition (SI) of cell proliferation found in HCAEC and HCMSMC was achieved with drug concentrations more than 10 times beyond the maximal plasma level (MPL), resulting in a SI/MPL-ratio > 1. CONCLUSION: Thus, the anti-restenotic effects of systemically administered abciximab reported in the ISAR-SWEET-study were not caused by a direct inhibitory effect on ICAM-1 expression, migration or proliferation

Phytochemical and sensorial characterization of Hyssopus officinalis subsp. aristatus (godr.) Nyman (Lamiaceae) by GC–MS, HPLC–UV–DAD, spectrophotometric assays and e-nose with aid of chemometric techniques

The aim of this study was to evaluate the potential compositional differences among different populations of H. officinalis subsp. aristatus (Godr.) Nyman. The plant specimens were collected in different locations in Western Balkans (Kosovo and Albania) and subjected to phytochemical profiling (GC–MS for their essential oils and HPLC-UV-DAD for fingerprinting of their solvent extractable phytochemicals). Antioxidant capacity, total flavonoid and phenol contents were measured using different assays. Out of the five location considered, the specimen from one location displayed significant differences both in terms of essential oil composition and of polyphenolic total content. The electronic nose measurements used to characterize their aromatic profile, was able to clearly discriminate the accessions, indicating a good correlation, in particular, with the marked chemotypic difference established by essential oil profiling (1,8-cineol vs. isopinocamphone/camphone). H. officinalis subspp. aristatus (Godr.) Nyman may constitute an interesting subject for further studies on the effect of genetic and environmental factors, or of their combinations, on its chemotypic expression and sensorial properties