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ABSTRACTA validated framework developed to analyse railway occupant safety is presented here. The inexistence of restraints and the larger distance between contact features for the railway cabin interior decreases the predictability on the kinematics of its occupants. Simulation results are evaluated considering the severity of the injuries, assessed and quantified using the relevant criteria. It was introduced a head padding that conducted to a reduction of the Head Injury Criterion (HIC) but worsening the value of neck-bending moment in extension (NBME). Finally, the multi-objective optimization procedures are applied to achieve a relevant reduction in injuries. With the implementation of a pad with 42 mm thickness and with a reduction of 8.2% of the backseat plate thickness, is obtained a 41% reduction of the HIC but at the cost of an increase of 49% of the NBME index, though this design allows keeping all injury indices below moderate threshold value.

Coating process is an important step in the manufacturing of different products, such as paper, adhesive and magnetic tapes, photographic films, and many other. The tensioned web roll coating is one the several methods used by different industries. It relies on the elastohydrodynamic action between the fluid and the tensioned substrate for transferring and applying the liquid. The main advantage of this method is its ability to apply very thin liquid layers with less sensitivity to mechanical tolerance at relative small cost. Despite its industrial application, theoretical analysis and fundamental understanding of the process are limited. This work analyses this elastohydrodynamic action by solving the differential equations that govern the liquid flow, described by the Navier–Stokes equation, and the web deformation, modelled by the cylindrical shell approximation. The goal is to determine the operating conditions at which the process is two dimensional and defect free. The equations are discretized by the Galerkin/finite‐element method. The resulting non‐linear system of equations is solved by Newton's method coupled with pseudo‐arc‐length continuation in order to obtain solutions around turning points. The theoretical results are used to construct an operating window of the process that is in agreement with limited experimental data. Copyright © 2003 John Wiley & Sons, Ltd.

Conventional drying of coated substrates usually uses air impingement to support and heat the coated web. Because of the high‐velocity air flow, most of the heat is transferred by convection and the heat transfer coefficient is not uniform, leading to drying defects. To overcome this and obtain a high uniform heat transfer coefficient, the energy is supplied to the backside of the substrate by conduction through a thin air‐layer between a heated plate and the moving substrate. To obtain heat transfer coefficients comparable to those from air impingement, the distance between the web and plate has to be very small, yet not touch the plate. It is essential to form and control a thin, uniform and stable air layer between the substrate and heating plate by wrapping the moving web over a plate with a large radius of curvature. Air‐layer thickness entrained between the web and plate is related to the air flow rate between the two surfaces. The flow between a moving flexible substrate and curved solid surface was analyzed by theory and experiments to examine this elastohydrodynamic action and changes in air‐layer thickness with the plate geometry, substrate material, and operating conditions. The theoretical model consisted of the Navier–Stokes equation to describe the air motion and cylindrical shell approximation to model the web deformation. Differential equations describing the problem were solved by the Galerkin's/finite‐element method. The nonlinear algebraic system was solved by Newton's method with initialization by pseudo‐arc‐length continuation. In experiments, the distance between the moving web and curved plate was measured at different operating conditions. The predicted air‐layer thicknesses agreed well with experimental measurements. The air‐layer thickness is controlled by the flow in the plate entrance.

Manoalide is a potent antiinflammatory marine natural product and a direct inactivator of venom phospholipase A2 (PLA2; EC 3.1.1.4). Manoalide has been shown to irreversibly inhibit PLA2, with the corresponding modification of a selective number of lysine residues. The mechanism of inactivation has not yet been elucidated and structure-activity relationship studies were, therefore, performed in order to determine the contributions of the various functional groups incorporated in the gamma-hydroxybutenolide, alpha-hydroxydihydropyran, and trimethylcyclohexenyl ring systems to the efficacy (irreversibility) and potency of this series of inhibitors. These studies indicate that 1) the presence of the hemiacetal in the alpha-hydroxydihydropyran ring is required for irreversible binding of manoalide, 2) the gamma-hydroxybutenolide ring is involved in the initial interaction of manoalide with PLA2, and 3) the hydrophobic nature of the trimethylcyclohexenyl ring system allows nonbonded interactions between manoalide and PLA2 that enhance the potency of these analogs. These structure-activity relationship studies suggest that the closed ring form of manoalide is the predominant molecular species that accounts for the selective and potent inhibition of PLA2 by manoalide. Elucidation of the mechanism awaits further detailed physicochemical studies on the structure of the manoalide (analog)-protein adducts in model systems and using PLA2.

The flow pattern at low Reynolds number in the neighborhood of a sudden contraction is very sensitive to the mechanical behavior of the flowing fluid. A large extensional viscosity leads to vortex enhancement in the corner region of the flow of a non-Newtonian fluid in such geometry. In the corresponding flow of a Newtonian fluid, these vortices are much weaker and smaller. Moreover, the extension-thickening behavior of most polymeric liquids leads to higher viscous dissipation effects in the predominantly extensional flow, as compared to typical shear flows. The flow and temperature fields for this problem have been obtained from numerical integration of the conservation equations, aiming at applications related to extrusion and capillary rheometry of polymeric liquids. To account for the flow dependence of the stress tensor, a generalized Newtonian model has been employed, including the dependence of the viscosity function on both the second and the third invariants of the rate-of-deformation tensor. The numerical solutions have been obtained via a finite-volume method. The case of a 4:1 circular contraction was investigated, with uniform temperature distribution at the solid boundaries. The fluid inlet temperature is equal to the temperature at the walls, so that thermal gradients in the fluid are due to viscous dissipation effects only. Comparisons between Newtonian and non-Newtonian results showed that the combined effect of viscous dissipation and enhancement of vortex activity significantly affects the temperature field. The practical significance of the results is discussed for extrusion processes and capillary rheometry.

The flow pattern at low Reynolds number in the neighborhood of a sudden contraction is very sensitive to the mechanical behavior of the flowing fluid. A large extensional viscosity leads to vortex enhancement in the corner region of the flow of a non-Newtonian fluid in such geometry. In the corresponding flow of a Newtonian fluid, these vortices are much weaker and smaller. Moreover, the extension-thickening behavior of most polymeric liquids leads to higher viscous dissipation effects in the predominantly extensional flow, as compared to typical shear flows. The flow and temperature fields for this problem have been obtained from numerical integration of the conservation equations, aiming at applications related to extrusion and capillary rheometry of polymeric liquids. To account for the flow dependence of the stress tensor, a generalized Newtonian model has been employed, including the dependence of the viscosity function on both the second and the third invariants of the rate-of-deformation tensor. The numerical solutions have been obtained via a finite-volume method. The case of a 4:1 circular contraction was investigated, with uniform temperature distribution at the solid boundaries. The fluid inlet temperature is equal to the temperature at the walls, so that thermal gradients in the fluid are due to viscous dissipation effects only. Comparisons between Newtonian and non-Newtonian results showed that the combined effect of viscous dissipation and enhancement of vortex activity significantly affects the temperature field. The practical significance of the results is discussed for extrusion processes and capillary rheometry.

ABSTRACTThe separation of a samarium (90%) and europium (10%) mixture in α-hydroxy isobutyric acid was performed in a new countercurrent electromigration system. The mobilities of these elements were estimated, and samarium of better than 99.9% purity was obtained. The equilibrium of multicoordinate complexes of these elements

Arachidonic acid release is induced in macrophages with diverse agonists including calcium ionophores, phorbol myristate acetate (PMA), okadaic acid, and the phagocytic particle, zymosan, and correlates with activation of cytosolic phospholipase A2 (cPLA2). The role of calcium and phosphorylation of cPLA2 in regulating arachidonic acid release was investigated. Zymosan induced a rapid and transient increase in [Ca2+]i. This in itself is not sufficient to induce arachidonic acid release since ATP and platelet activating factor (PAF), agonists that induce transient calcium mobilization in macrophages, induced little arachidonic acid release. Unlike zymosan, which is a strong activator of mitogen-activated protein kinase (MAPK), ATP and PAF were weak MAPK activators and induced only a partial and transient increase in cPLA2 phosphorylation (gel shift). However, ATP or PAF together with colony stimulating factor-1 (CSF-1) synergistically stimulated arachidonic acid release. CSF-1 is a strong MAPK activator that induces a rapid and complete cPLA2 gel shift but not calcium mobilization or arachidonic acid release. Arachidonic acid release was more rapid in response to CSF-1 plus ATP or PAF than zymosan and correlated with the time course of the cPLA2 gel shift. Although low concentrations of ionomycin induced a lower magnitude of calcium mobilization than ATP, the response was more sustained resulting in arachidonic acid release. A23187 and ionomycin induced weak MAPK activation, and a partial and transient cPLA2 gel shift. The MAPK kinase inhibitor, PD 98059 suppressed A23187-induced MAPK activation and cPLA2 gel shift but had little effect on arachidonic acid release. These results indicate that in macrophages a transient increase in [Ca2+]i and sustained phosphorylation of cPLA2 can act together to promote arachidonic acid release but neither alone is sufficient. A sustained increase in calcium is sufficient for inducing arachidonic acid release. However, PMA and okadaic acid induce arachidonic acid release without increasing [Ca2+]i, although resting levels of calcium are required, suggesting alternative mechanisms of regulation.

The rat mast cell line RBL-2H3.1 contains an 85-kDa cytosolic phospholipase A2 (cPLA2) that is very likely involved in liberating arachidonate from membrane phospholipid for the synthesis of eicosanoids following stimulation with either calcium ionophore or IgE/antigen. In this study, the intracellular location of cPLA2 was determined using immunofluorescence microscopy and immuno-gold electron microscopy. In nonstimulated cells, cPLA2 is distributed throughout the cytosol and is excluded from the nucleoplasm. Following cell activation with calcium ionophore, most of the cPLA2 translocates to the nuclear envelope, and the enzyme remains there during the entire period that ionophore is present. With IgE/antigen stimulation for 5 min, approximately 20-30% of the cPLA2 translocates to the nuclear envelope, and after 30 min of stimulation, most of the enzyme returns to the cytosol. Measurement of intracellular calcium using the dye Fura-2/AM shows that the level of calcium rises immediately after antigen is added, remains high for about 30 s, and then declines back to resting levels. Activation with calcium ionophore produces a 10-fold larger release of arachidonate than does stimulation with IgE/antigen. Thus, the results suggest that the extent of membrane binding of cPLA2 correlates with the release of arachidonate and that the site of arachidonate liberation is the nuclear envelope where many of the enzymes that oxygenate this fatty acid are located.

In a forward‐roll coating gap or nip, steady laminar flow of liquid between counter‐rotating cylinders or rolls is used to split the flow into a coated layer on one roll and a rejected layer on the other. Both layers have free surfaces in contact with air. Liquid may be carried into the gap as a layer on one or both rolls. If the arriving layer is not too thick, all of the liquid flows through the gap, a situation called pre‐metered. If the arriving layer is too thick, part of the liquid is rejected and runs back down the lower roll. The flow rate through the gap is said to be meteredand is not known a priori.

Luffolide (4) is a minor metabolite of the spongeLuffariellasp. from Palau. The structure of luffolide was determined by single crystal X-ray analysis. Luffolide is relatively unstable and undergoes a complex cyclization reaction to give the hexacyclic products5and6. Luffolide (4) has some of the anti-inflammatory properties of manoalide (1): this may help to define the chemical reaction between manoalide (1) and phospholipase A2.

Background: Handheld ultrasound devices allow for a bedside screening although quantitative parameters are not easily obtained. We aim to assess the reliability of visual qualitative evaluation of left ventricle (LV) compared with standard quantitative evaluation with 2D transthoracic echocardiography (TTE). Methods: Two cardiologists have reviewed 135 consecutive standard TTE examinations. Both observers visually assessed LV size, hypertrophy (LVH) and ejection fraction (EF). LV diameter, volume, wall thickness and EF (Teichholz and Simpson) were also measured by both observers. Visual and quantitative agreement and inter and intraobserver variability were calculated. Results: Image quality allowed for evaluation of 130 examinations. Visually assessed EF compared with Simpson had better consistency (Intraclass correlation coefficient [ICC] 0,91 IC95% 0,88-0,94) than with Teichholz (ICC 0,75 IC95% 0,66-0,82). We have also observed good interobserver agreement regarding visually assessed EF (ICC 0,81 IC95% 0,71-0,87) and Simpson EF (ICC 0,80 IC95% 0,70-0,89) as well as good intraobserver agreement (visual EF: ICC 0,81 IC95% 0,74-0,86; Simpson: ICC 0,89 IC95% 0,84-0,93). Regarding LVH we found moderate agreement between visual and quantitative assessment (weighted Kappa [wK] 0,44 (IC95% 0,32-0,56)), moderate interobserver agreement for quantitative assessment (ICC 0,59 IC95% 0,44-0,71) and poor interobserver agreement for visual assessment (wK 0,19 IC95% 0,08-0,30). Intraobserver variability regarding LVH visual estimation was moderate (wK 0,40 IC95% 0,29-0,52) and regarding LVH quantification was good (ICC 0,78 IC95% 0,70-0,84). LVH was visually overestimated in 25% of examinations. Regarding LV size, we found poor agreement between visual assessment and its quantification with end-diastolic diameter (wK 0,22 IC95% 0,06-0,39) and moderate agreement between visual assessment and end-systolic LV volume (wK 0,62 IC95% 0,47-0,77). Interobserver agreement regarding quantitative volume assessment was good (ICC 0,90 IC95% 0,85-0,94) and regarding visual assessment was moderate (wK 0,43 IC95% 0,26-0,70). We found good intraobserver variability of volume measurement (wK 0,64 IC95% 0,50-0,78) and of visual size assessment (ICC 0,96 IC95% 0,94-0,97). Conclusions: Visual LVEF assessment is consistent with quantitative assessment and should be regarded as a reliable parameter that can be obtained from bedside examination with a handheld device. Visual assessment of LV size and wall thickness is less reliable than its quantification and should be confirmed with standard measurements.