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431.
Heparin is widely prescribed as an anticoagulant medicine and is beneficial to millions of patients. However, the use of heparin in open‐heart surgery, where it enables a continuous flow of blood throughout the process, is still problematic. Its anticlotting properties are crucial for a successful operation, but after surgery the patient's blood needs to return normal and acquire its former ability to coagulate. If this process fails, the outcome may prove fatal. Currently, protamine sulfate is used to neutralize heparin after open‐heart surgery. However, protamine itself causes allergic reactions and other side effects and is sometimes fatal. For this reason, the finding of new heparin antagonists or much safer methods for heparin removal from blood is currently of great interest. Recently we have reported on the synthesis of calix[8]arene polycations that have shown an exceptional neutralization power towards heparin both in physiological solution and in blood. In this work, we have studied the grafting of these calix[8]arene derivatives onto a polymeric matrix with the aim to obtain a new polymeric material appropriate for the design and realization of filters or membranes able to effectively remove heparin from blood. In this way, also the side effects connected to systemic administration of heparin antagonists are avoided. Besides the synthesis, preliminary results on the neutralization capacity towards heparin, both in physiological solution and in blood, are reported. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
432.
María Luisa Jiménez Tommaso Bellini 《Current Opinion in Colloid & Interface Science》2010,15(3):131-144
The response of charged colloids to electric fields is determined by combined phenomena occurring first in the electric double layer to then develop into long-range perturbations of ion concentration, local fields, and solvent flows. When particles are non-spherical, the loss of symmetry affects the short- and long-ranged processes modifying their behavior as observed through their electrophoretic mobility, dielectric permittivity, and electro-optical response. Recent measurements and theoretical developments have revealed phenomena characteristic for non-spherical particles, such as the doubling of the relaxations in the dielectric spectra, the appearance of torque-inducing hydrodynamic flows, and the anomalous perpendicular alignment. In this article we discuss in a unifying frame the recent experimental and theoretical progresses about the electrokinetic behavior of charged non-spherical colloids. 相似文献
433.
B. V. Robouch I. V. Kutcherenko M. Cestelli Guidi A. Kisiel A. Marcelli P. Robouch M. Piccinini A. Nucara R. Triboulet E. Burattini J. Cebulski E. M. Sheregii J. Polit 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,84(2):183-195
Similar ternary semiconductors are sometimes associated with widely different structures characterized by different site occupation preferences. We have used far-infrared (FIR) spectra to determine the site occupation preference coefficients for three ternary semiconductor alloys: ZnCdTe, ZnHgTe and CdHgTe and, in the case of ZnHgTe, have validated it by X-ray absorption fine structure (EXAFS) analysis. While ZnCdTe spectra exhibit the canonical configuration with eight phonon lines free of vibrational defect lines and only a slight departure from a random ion distribution, CdHgTe spectra show the eight canonical phonon modes plus an additional vibrational defect line and constant preference coefficients. In contrast, two defect lines and only four modes characterize ZnHgTe spectra, as extreme preferences prevent the formation of two of the five expected tetrahedral configuration arrangements. Moreover, for this system, comparison with EXAFS data points out the vibrational nature of both the extra lines. The analysis clearly shows that assuming a Bernoulli distribution of the component configurations of semiconductors may lead to wrong assessments of the evolution of its properties with relative content. 相似文献
434.
Brunilde Castano Tommaso Pedrazzini Massimo Sisti Emma Gallo Fabio Ragaini Nicola Casati Alessandro Caselli 《应用有机金属化学》2011,25(11):824-829
The synthesis and characterization of copper(I) complexes of the novel pyridine‐containing macrocyclic ligand (PC‐L) and their use as catalysts in the Henry reaction are reported. The pyridine‐based 12‐membered tetraaza macrocyclic (PC‐L) ligand 1 can be obtained in good overall yield (85%) from commercially available starting materials. The Cu(I) complexes showed good catalytic activities in the Henry reaction of different aldehydes and nitroalkanes. Remarkable diastereoselectivity was observed when isatine was reacted with nitroethane under catalytic conditions. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
435.
Tommaso Flaminio 《Archive for Mathematical Logic》2007,46(3-4):301-319
In this paper we investigate the problem of testing the coherence of an assessment of conditional probability following a
purely logical setting. In particular we will prove that the coherence of an assessment of conditional probability χ can be
characterized by means of the logical consistency of a suitable theory T
χ defined on the modal-fuzzy logic FP
k
(RŁΔ) built up over the many-valued logic RŁΔ. Such modal-fuzzy logic was previously introduced in Flaminio (Lecture Notes in Computer Science, vol. 3571, 2005) in order
to treat conditional probability by means of a list of simple probabilities following the well known (smart) ideas exposed
by Halpern (Proceedings of the eighth conference on theoretical aspects of rationality and knowledge, pp 17–30, 2001) and
by Coletti and Scozzafava (Trends Logic 15, 2002). Roughly speaking, such logic is obtained by adding to the language of RŁΔ a list of k modalities for “probably” and axioms reflecting the properties of simple probability measures. Moreover we prove that the satisfiability problem for
modal formulas of FP
k
(RŁΔ) is NP-complete. Finally, as main result of this paper, we prove FP
k
(RŁΔ) in order to prove that the problem of establishing the coherence of rational assessments of conditional probability is NP-complete.
相似文献
436.
Donata Di Tommaso Roberto Calabrese Domenico Rotilio 《Journal of separation science》1998,21(10):549-553
Hydroxytyrosol (HTy) is a potent natural antioxidant found in olive oil and in mill waste waters. Although wines are rich in polyphenols, hydroxytyrosol has not been identified in wines so far. We have analyzed ten wines from different grape varieties grown in several Italian regions, using a gas-chromatograph coupled to a mass selective detector (GC-MS). Solid-phase extraction of wine samples was performed on a C18 column, with ethyl acetate used as eluting agent. Eluates were derivatized with bis(trimethylsilyl)trifluoroacetamide (BSTFA) and analyzed by GC-MS using one target and two qualifying ions. The detection limit was 15 pg/μL, with 49% average recovery. Under these experimental conditions hydroxytyrosol was detected in all wines analyzed. Its average concentrations in red and white wines were 4.0 mg/L and 1.9 mg/L, respectively. 相似文献
437.
Sara Gmez Natalia Rojas-Valencia Tommaso Giovannini Albeiro Restrepo Chiara Cappelli 《Molecules (Basel, Switzerland)》2022,27(2)
We unravel the potentialities of resonance Raman spectroscopy to detect ibuprofen in diluted aqueous solutions. In particular, we exploit a fully polarizable quantum mechanics/molecular mechanics (QM/MM) methodology based on fluctuating charges coupled to molecular dynamics (MD) in order to take into account the dynamical aspects of the solvation phenomenon. Our findings, which are discussed in light of a natural bond orbital (NBO) analysis, reveal that a selective enhancement of the Raman signal due to the normal mode associated with the C–C stretching in the ring, , can be achieved by properly tuning the incident wavelength, thus facilitating the recognition of ibuprofen in water samples. 相似文献
438.
Takashi Arima Maria Cristina Carrisi Sebastiano Pennisi Tommaso Ruggeri 《Entropy (Basel, Switzerland)》2022,24(1)
A relativistic version of the rational extended thermodynamics of polyatomic gases based on a new hierarchy of moments that takes into account the total energy composed by the rest energy and the energy of the molecular internal mode is proposed. The moment equations associated with the Boltzmann–Chernikov equation are derived, and the system for the first 15 equations is closed by the procedure of the maximum entropy principle and by using an appropriate BGK model for the collisional term. The entropy principle with a convex entropy density is proved in a neighborhood of equilibrium state, and, as a consequence, the system is symmetric hyperbolic and the Cauchy problem is well-posed. The ultra-relativistic and classical limits are also studied. The theories with 14 and 6 moments are deduced as principal subsystems. Particularly interesting is the subsystem with 6 fields in which the dissipation is only due to the dynamical pressure. This simplified model can be very useful when bulk viscosity is dominant and might be important in cosmological problems. Using the Maxwellian iteration, we obtain the parabolic limit, and the heat conductivity, shear viscosity, and bulk viscosity are deduced and plotted. 相似文献
439.
Considering the hyperbolic symmetric system of moments associated with the relativistic Boltzmann-Chernikov equation and closed
through procedures of Extended Thermodynamics, we determine numerically the maximum characteristic wave velocity for degenerate
and non-degenerate gases. As predicted by recent results, this velocity increases monotonically with respect to the number
of moments and tends asymptotically to the speed of light. We show that many moments are often required to approach with a
good approximation the speed of light. The dependence of the maximum characteristic wave velocity on the properties of the
materials is also investigated and it turns out that it depends significantly on the chemical potential only in the case of
Fermions gases.
Received April 24, 1999 相似文献
440.
Di Tommaso A. Neubauer U. Pantuso A. Rostasy F. S. 《Mechanics of Composite Materials》2001,37(4):327-338
This paper presents an evaluation of the results obtained from an initial study carried out at the IBMB, Technical University of Braunschweig, on the influence of temperature on adhesively bonded plate-concrete joint systems. The results of a theoretical model are also presented. The type of specimen used in this study is a three-point bending beam. The concrete specimens were prismatic in form, 100 × 100 × 700 mm without an internal steel reinforcement, strengthened at the intradoss with two types of UD CFRP lamina 20 mm wide and 590 mm long of thickness 1.4 mm for the E = 300 GPa type and 1.24 mm for the E = 175 GPa type. The plate-bonded specimens were designed to produce bending failure under a load, by not bonding the lamina and the concrete around the midspan of the specimens. The specimens were tested to failure at –100°, –30°, and +40°C after an approximately homogeneous temperature distribution within the concrete specimen has been reached. For comparison only, specimens of the same type were tested to failure at room temperature. The results obtained showed varying behavior of the bonded plate-concrete joint depending on variations in temperature. Furthermore, they showed different failure mechanisms. Greater reductions in the ultimate bond force were recorded for the test specimens strengthened with lamina having a high elastic modulus. A reasonable correlation was found between the experimental and theoretical results. 相似文献