Assessment of the influence of the compliant aortic root on aortic valve mechanics by means of a geometrical model

In recent years several researchers have suggested that the changes in the geometry and angular dimensions of the aortic root which occur during the cardiac cycle are functional to the optimisation of aortic valve function, both in terms of diminishing leaflet stresses and of fluid-dynamic behaviour. The paper presents an analytical parametric model of the aortic valve which includes the aortic root movement. The indexes used to evaluate the valve behaviour are the circumferential membrane stress and the stress at the free edge of the leaflet, the index of bending strain, the bending of the leaflet at the line attachment in the radial and circumferential directions and the shape of the conduit formed by the leaflets during systole. In order to evaluate the role of geometric changes in valve performance, two control cases were considered, with different reference geometric configuration, where the movement of the aortic root was ignored. The results obtained appear consistent with physiological data, especially with regard to the late diastolic phase and the early ejection phase, and put in evidence the role of the aortic root movement in the improvement of valve behaviour.     

Thioglycolate-elicited rat macrophages exhibit alterations in incroporation and oxidation of fatty acids

Incorporation and oxidation of fatty acids (FA) were investigated in resident and thioglycolate-clicited (TG-elicited) rat macrophages (Mϕ). Both cell types presented a time-dependent incorporation of [¹⁴C]-labeled palmitic acid (PA), oleic acid (OA), linoleic acid (LA), and arachidonic acid (AA) up to 6h. The total amount of [¹⁴C]-FA incorporated by resident Mϕ after 6 h was: AA>PA=LA>OA. TG-elicited cells presented a 50% reduction in the incorporation of LA, PA, and AA, whereas that of OA remained unchanged as compared to resident Mϕ. The FA were oxidized by resident Mϕ as follows: LA>OA>PA>AA. TG elicitation promoted a reduction of 42% in LA oxidation and a marked increase in AA oxidation (280%). The increased oxidation of AA in TG-elicited cells may account for the lower production of prostaglandins in Mϕ under these conditions. The full significance of these findings for Mϕ function, however, remains to be examined.     

Multifold behavior of the information transmission by the quantum 3-switch

Quantum Information Processing - A Correction to this paper has been published: https://doi.org/10.1007/s11128-019-2234-5     

Influence of malting and lactic acid fermentation on functional bioactive components in cereal‐based raw materials: a review paper

Driven by increased health awareness among consumers, the production of foods and beverages enriched with functional bioactive components is gaining more attention. Malting and lactic acid fermentation are biotechnological processes having potential for producing functional foods and beverages. Due to various biochemical and enzymatic induced changes in raw materials, malting of cereal grains and probiotic lactic acid fermentation of plant‐based media increases the nutritional quality of treated raw materials. The improved nutritional quality is attributed to the accumulation of functional bioactive components along with the degradation of anti‐nutritional components. The selection of raw materials and process parameters are important factors to be considered for increasing the functional bioactive components such as dietary fibres, antioxidants and probiotics. This review article reports the current knowledge on the changes of bioactive components during malting and lactic acid fermentation using probiotic bacterial strains. Process parameters which affect the concentration of bioactive components in raw materials will also be described.     

Lightning return stroke current identification via field measurements

 An inverse procedure is presented for identifying and reconstructing the waveform of the lightning return stroke current. It is based only on the acquisition of the electromagnetic field radiated by the discharge channel in various locations on the ground and at various frequencies, and requires no information about the channel base current. The fundamental idea is shown to come from an electrostatic problem in which the linear charge density of a vertical thin wire is determined starting from the measured field. Three versions of this procedure have been developed: in the first, the identification is carried out by means of the measurement of the electric field at various distances from the lightning channel at a given frequency; in the second, only two sensors for the electric field are necessary, but various sampling frequencies; in the third, only one observation point is needed, for the measurement of both the electric and the magnetic field. A simulated validation of all the approaches is provided as well as a detailed analysis of their numerical accuracy. Received: 4 April 2001/Accepted: 30 April 2001     

Gamma dose rate calculation and mapping of piemonte (North-West Italy) from gamma spectrometry soil data

In this study the air gamma dose rate map of Piemonte, a region in the North-West of Italy, was produced from gamma spectrometry soil data. Soil samples collected in 110 different sites of Piemonte were analysed with Hyperpure Germanium (HPGe) detectors (30% relative efficiency), which allow the evaluation of the activity concentrations of natural radionuclides and (137)Cs. Then, using the available mathematical models, the gamma absorbed dose rate in air due to radionuclides was calculated. The contribution of the cosmic radiation to the total absorbed dose rate, which depend on the site altitude was also evaluated and added to the soil contribution. Finally, the map of the whole region was obtained by fitting the dose rate values of the different sites with kriging algorithms.     

Hybrid MCM-41 grafted by a general microwave-assisted procedure: a characterization study

Hybrid materials obtained through a Microwave-assisted grafting of organic functional groups on mesoporous silica (MCM-41 type) have been characterized by X-ray powder diffraction, TG-DSC, N₂ adsorption, solid state ¹³C- and ²⁹Si-NMR, TEM and SEM. The studied grafting procedure is effective in the preparation of hybrid organosilicas under solvent-free conditions. Microwaves allows an ultra-fast and clean functionalization of the mesoporous materials and the method has been applied to produce a wide series of functional materials. The hybrid materials maintain the original mesoporous structure when the loading of linked organic groups does not exceed 10 %. In this cases, the slight pore volume reduction is linearly correlated to the organic amount in the product. If functional groups able to interact among them through hydrogen bond are used, hybrid materials exhibit high Organic/SiO₂ ratios and low pore volumes due to the formation of a network occluding the pores, where functional groups of free organosilane molecules interacts with the functional groups of molecules linked to the matrix. NMR data confirm that the network is composed by organosilane molecules linked or not to the framework. Acid washing is able to labilize hydrogen bond and open the network. In the case of bulky but chemically inert functionalising agents the network is not produced.     

Effect of oxytocin on transepithelial transport of water and Na+ in distinct ventral regions of frog skin (Rana catesbeiana)

Thoracic, abdominal, and pelvic fragments of ventral skin of Rana catesbeiana were analysed regarding the effect of oxytocin on: (1) transepithelial water transport; (2) short-circuit current; (3) skin conductance and electrical potential difference; (4) Na+ conductance, the electromotive force of the Na+ transport mechanism, and shunt conductance; (5) short-circuit current responses to fast Na+ by K+ replacement in the outer compartment, and (6) epithelial microstructure. Unstimulated water and Na+ permeabilities were low along the ventral skin. Hydrosmotic and natriferic responses to oxytocin increased from thorax to pelvis. Unstimulated Na+ conductance was greater in pelvis than in abdomen, the other electrical parameters being essentially similar in both skin fragments. Contribution of shunt conductance to total skin conductance was higher in abdominal than in pelvic skin. Oxytocininduced increases of total skin conductance, Na+ conductance, and shunt conductance in pelvis were significantly larger than in abdomen. An oscillatory behaviour of the short-circuit current was observed only in oxytocin-treated pelvic skins. Decrease of epithelial thickness and increase of mitochondria-rich cell number were observed from thorax to pelvis. Oxytocin-induced increases of interspaces were more conspicuous in pelvis and abdomen than in thorax.     

Cardiomyopathy and pre-excitation syndrome of a familial nature

Amniotic fluid insulin levels and the lecithin-sphingomyelin ratio were determined in 62 samples of 33 insulin-dependent diabetic patients from the 29th to the 44th week of gestation inclusive and in 42 samples of 38 gestational diabetic patients from the 35th to the 43rd week of gestation inclusive. (Gestational age was measured by ultrasonography.) The level of insulin in the amniotic fluid did not appear to affect the lecithin-sphingomyelin ratio.