Degenerate non-stationary differential equations with delay in Banach spaces

A generalization of the operator method by Grisvard is used to ensure weak and strict solutions to some degenerate differential equations with delay in Banach spaces, whose operator coefficients are time depending. Some applications to ordinary and partial differential equations with delay are described.     

Free radicals formed by addition of antimalaric artemisinin (Qinghaosu,QHS) to human serum: an ESR-spin trapping investigation

The antimalaric drug artemisinin (QHS) is believed to operate through a mechanism initiated with the cleavage of its endoperoxidic bond induced by transition metal ions. An ESR investigation of the reaction of QHS with human serum in the presence of two spin trapping agents has led to the detection of spin adducts of carbon-centred radicals. Experiments carried out replacing the human serum with iron(II) salts led to the observation of the same spin adducts, thus supporting previous suggestions that alsoin vivo the drug operatesvia a radical-based mechanism. UV irradiation of QHS also led to the trapping of transient free radicals.     

Modelling and Optimal Receding-horizon Control of Maritime Container Terminals

The main objective of this paper consists in modelling, optimizing, and controlling container transfer operations inside intermodal terminals. More specifically, maritime container terminals are here considered, involving three kinds of transportation modes, i.e., maritime, rail, and road transport. Generally speaking, an intermodal port terminal can be seen as a system of container flows with two interfaces, towards the hinterland and towards the sea, respectively. Moreover, inside a terminal, unloading operations of inbound containers, container storage, and loading operations of outbound containers are carried out. A simple model for maritime container terminals is proposed in this paper. In the model, a system of queues represents the standing of containers and their movements inside the terminal. The dynamic evolutions of these queues are described by discrete-time equations, where the state variables represent the queue lengths and the control variables take into account the utilization of terminal resources such as load/unload handling rates. On the basis of the proposed model, an optimization problem is defined that consists in minimizing the transfer delays of containers in the terminal. The problem is stated as an optimal control problem whose solution is sought by adopting a receding-horizon strategy.      

A multimodality investigation of cerebral hemodynamics and autoregulation in pharmacological MRI

Pharmacological MRI (phMRI) methods have been widely applied to assess the central hemodynamic response to pharmacological intervention as a surrogate for changes in the underlying neuronal activity. However, many psychoactive drugs can also affect cardiovascular parameters, including arterial blood pressure (BP). Abrupt changes in BP or the anesthetic agents used in preclinical phMRI may impair cerebral blood flow (CBF) autoregulation mechanisms, potentially introducing confounds in the phMRI response. Moreover, relative cerebral blood volume (rCBV), often measured in small-animal phMRI studies, may be sensitive to BP changes even in the presence of intact autoregulation. We applied laser Doppler flowmetry and MRI to measure changes in CBF and microvascular CBV induced by increasing doses of intravenous norepinephrine (NE) challenge in the halothane-anesthetized rat. NE is a potent vasopressor that does not cross the blood-brain barrier and mimics the rapid BP changes typically observed with acute drug challenges. We found that CBF autoregulation was maintained over a BP range of 60-120 mmHg. Under these conditions, no significant central rCBV responses were observed, suggesting that microvascular rCBV changes in response to abrupt changes in perfusion pressure are negligible within the autoregulatory range. Larger BP responses were accompanied by significant changes in both CBV and CBF that might confound the interpretation of phMRI results.     

Critical behavior of CP(1) at theta=pi, Haldane's conjecture, and the relevant universality class

Using an approach to analyze the theta dependence of systems with a theta term we recently proposed, the critical behavior of CP(10 at theta=pi is studied. We find a region outside the strong coupling regime where Haldane's conjecture is verified. The critical line, however, does not belong to the universality class of the Wess-Zumino-Novikov-Witten model at topological coupling k=1 since it shows continuously varying critical exponents.     

A chiral probe for the detection of Cu(II) by UV, CD and emission spectroscopies

The synthesis and characterization of the new chiral ligand 2, based on a BINOL-tren (tren = tris(2-aminoethyl)amine) conjugate, in enantiomerically pure form, are reported. UV-Vis spectrophotometric and spectrofluorimetric studies at variable pH show that the incorporation of a phenolic functionality in close proximity to the polyamino fragment of the molecule causes a dramatic variation of the acid-base and coordination properties of the molecule; the major role of this functionality in determining the selectivity observed in the complexation of Cu(2+), when compared with Zn(2+) and Ni(2+), at pH = 5 in aqueous MeOH, has been clarified, also by comparison with the spectroscopic and coordination properties of model compound 3, bearing protected OMe functionalities. The peculiar absorbance, emission and chiroptical properties of the binaphthyl fragment incorporated in compound 2 can be used for the selective detection of Cu(2+) using three different and potentially orthogonal techniques, namely UV, CD and fluorescence spectroscopies.     

Rhenium fac tricarbonyl bisimine complexes: biologically useful fluorochromes for cell imaging applications

A series of lipophilic and hydrophilic fac tricarbonyl rhenium bisimine complexes have been prepared, their membrane-permeabilities explored in liposomes and their potential for application in fluorescence microscopy cell imaging demonstrated in the first application of MLCT-fluorescent rhenium complexes in cell imaging.