Antonella Fontana

At Pantelleria island, Sicily Channel, metaluminous to peralkaline felsic magmas were erupted in a wide dynamical range: lava flows, plinian to strombolian eruptions and pyroclastic flows. We present the results of melt inclusions study from some old eruptive units (age 190-80 ka), more precisely: six strombolian / ultra-strombolian fallout deposits and one unwelded ignimbrite. These deposits are exposed in the north-east to north-west sides of the island along coastal scars or in caldera northern inner wall, and else in the southern portion of island. These eruptive units are not correlative and the rationale of this study was to acquire the widest possible data set of pre-eruptive volatile contents in quickly cooled products (i.e. excluding all the welded ignimbrites) in order to compare with existing and growing FT-IR data obtained on the Green Tuff plinian and more recent strombolian eruptions. All the studied products are pantelleritic in composition with an Na + K/Al ratio in ...

Rate constants for the enolisation reactions of title compounds have been measured by their rates of halogenation at 25 °C in water, in several buffers, in dilute hydrochloric acid, in dilute sodium hydroxide, and in the presence of some metal ion salts. The results have been ...

Benzenesulfonamides bearing various substituted (hetero)aryl rings in the para-position were prepared by palladium nanoparticle-catalyzed Suzuki-Miyaura cross-coupling reactions and evaluated as human carbonic anhydrase (hCA, EC 4.2.1.1) inhibitors against isoforms hCA I, II, IX, and XII. Most of the prepared sulfonamides showed low inhibition against hCA I isoform, whereas the other cytosolic isoenzyme, hCA II, was strongly affected. The major part of these new derivatives acted as potent inhibitors of the tumor-associated isoform hCA XII. An opposite trend was observed for phenyl, naphthyl, and various heteroaryl substituted benzenesulfonamides which displayed subnanomolar hCA IX inhibition while poorly inhibiting the other tumor-associated isoform hCA XII. The inhibition potency and influence of the partially restricted aryl-aryl bond rotation on the activity/selectivity were rationalized by means of X-ray crystallography of the adducts of hCA II with several 4-arylbenzenesulfonamides.

ABSTRACT The growing interest in the study of membrane-active ion (in particular, anion) transporters motivates the investigation of the mechanisms that underlie the transport process. The attention of the scientific community is largely due to the great importance of transmembrane ion transport phenomena in many diseases. In this paper we investigated the role of calix[6]arene-based pseudorotaxanes and rotaxanes on transmembrane vehiculation of ions across the bilayer of liposomes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC; diameter 100 nm). We evaluate the effect of these interlocked systems on the properties of the bilayer and on membrane permeability towards chloride and 5(6)-carboxyfluorescein. These findings may pave the way to the construction of new generations of pharmacological systems regulating the transport of Cl-.

The present report describes the case of a 55-year-old woman who suffered from cardio-embolic stroke originating from malignant fibrous histiocytoma (MFH) localized on the mitral valve. The patient underwent transthoracic two-/three-dimensional and transoesophageal echocardiography which demonstrated the mass protruding in the outflow tract of the left ventricle. Differential diagnosis had to be made with other masses in the left ventricle, such as thrombi, vegetations, and cardiac tumours. Surgery was performed to remove the tumour and the surgery findings confirmed echocardiographic images. Primary cardiac tumours are a rare entity, and their incidence is approximately 0.0017-0.019%. The majority of them are benign, but in a quarter of cases they are malignant. This case is an example of an MFH which caused embolism to the central nervous system.

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Three years after surgical resection of oesophageal tumour, during the regular instrumental oncologic follow-up performed by thoracic computed tomography scan in an otherwise asymptomatic 48-year-old man, a left ventricular mass was detected. It developed during a 6-month-period, and at the time of discovery it measured 63 × 61 mm. The mass was further evaluated with echocardiography and cardiac magnetic resonance imaging, and a histology specimen was obtained by myocardial biopsy, revealing it was a metastasis from the primitive tumour, in the absence of other organ involvement. The diagnostic process and possible therapeutic options for solitary intracardiac metastasis in the absence of involvement of other organs are briefly discussed.

The use of resynchronization therapy for the treatment of left ventricular (LV) systolic dysfunction in children has been expanding. Because QRS duration is not a reliable indicator of the presence or severity of dyssynchrony in every case, additional methods of quantitation of ...

We present the case of a man with severe aortic stenosis in whom diagnosis was established by evaluating the transvalvular gradient from the right parasternal view, since classical measurements from the apical five-chamber view were discordant with the indexed aortic valve area obtained in the short-axis view.

ABSTRACT A benchmark biochemical reaction is here theoretically investigated by means of a perturbative approach in order to model each reaction step. The reaction is the flavin-indole electron transfer, involving also a spin-state relaxation of the ionic complex. The whole reaction path is modeled and the kinetics of the process is studied. The dipolar interaction between the two radicals is explicitly considered during the dynamic evolution of the system in order to investigate the proper conditions for the triplet-to-singlet transition to occur.

We have designed and synthesized two amphiphilic calix[6]arene derivatives, CA8 and CA18, that combine the potential to act as wheel components for pseudorotaxane structures with the self-assembly features typical of surfactant molecules in aqueous solution. Their endo-cavity recognition and selfaggregation properties were compared with those of a non-amphiphilic analogue, C8. TEM, DLS, and fluorescence experiments show that in water the amphiphilic calixarenes form vesicle- and micelle-like aggregates. The size, nature and properties of such aggregates depend on the length of the alkyl chain anchored at the lower rim of the calix[6]arene skeleton, as well as on the inclusion of a molecular guest into the wheel. Specifically, the release of a fluorescent guest entrapped inside the CA8 vesicles is accelerated in the presence of dioctylviologen axles that can pierce the calixarene cavity.

Alzheimer's disease (AD) is characterized by irreversible and progressive loss of memory and cognition and profound neuronal loss. Current therapeutic strategies for the treatment of AD have been directed to a variety of targets with the aim of reversing or preventing the disease but, unfortunately, the available treatments often produce no significant clinical benefits. During the last decades compounds that inhibit or modulate γ-secretase, reducing β amyloid (Aβ) levels, have been considered as potential therapeutics for AD. Among these the (R)-enantiomer of flurbiprofen (FLU) seems to be very promising, but it shows low brain penetration. In this study, in order to improve the properties of FLU against Alzheimer's pathogenesis we synthesized some novel FLU lipophilic analogues. Lipophilicity of the new molecules has been characterized in terms of clogP, log K(C18/W) and log K(IAM/W) values. Permeability has been determined in both gastrointestinal PAMPA (PAMPA-GI) at different pH values and in brain blood barrier PAMPA (PAMPA-BBB) models. They were also tested for their ability to inhibit in vitro γ-secretase activity using rat CTXTNA2 astrocytes. Interestingly, the investigated molecules demonstrated to reduce Aβ 42 levels without affecting the amyloid precursor protein APP level in a clear concentrations-dependent manner.