Imidazo‐pyridine (Ia) und (Ib) reagieren nach Vilsmeyer zu den Aldehyden (II), die mit Natriumborhydrid zu den Alkoholen (III) und mit Methylmagnesiumiodid zu den Alkoholen (IV) umgesetzt werden können.

Phentolamine, dihydroergocristine and isoxsuprine were compared for their effects on the blood pressure in anaesthetized normotensive rats, in rats made hypotensive by ganglionic blockade or by pithing and in rats with noradrenaline-induced hypertension. Their ability to inhibit pressor responses elicited by electrical stimulation of the posterior hypothalamus and of the sympathetic outflow from the spinal cord was also investigated. All three drugs appeared very potent in inhibiting noradrenaline-induced hypertension and caused a dose-dependent fall in blood pressure in normotensive rats, which however was less pronounced with dihydroergocristine than with phentolamine and isoxsuprine. In hypotensive rats, dihydroergocristine caused a rise in blood pressure. At higher doses than those required to block noradrenaline-induced hypertension, the three drugs inhibited pressor responses elicited by electrical stimulation and were equally active on peripherally- and centrally-evoked responses. Simultaneous recording of heart rate and blood pressure, both in anaesthetized and in pithed rats, indicated a reflex origin for phentolamine-induced tachycardia and a direct cardiac stimulation for isoxsuprine. Reflex changes of heart rate were not observed with dihydroergocristine.

No abstract

L'articolo prende spunto dall'evoluzione di alcuni paradigmi teorici legati alla proposta di Walter J. Ong relativi alle variazioni delle modalitÀ di pensiero e delle fasi dell'apprendimento nel passaggio a una cultura della seconda oralitÀ. Si propongono alcuni esempi delle variazioni degli stili attentivi e delle abilitÀ mnestiche negli adolescenti che frequentano assiduamente ed esclusivamente le nuove tecnologie rappresentate dai videogame e da Internet. Infine si offrono esempi di nuove modalitÀ didattiche e approcci educativi innovativi che prendono in considerazione le variazioni delle intelligenze dei nativi digitali, con particolare riferimento all'esperienza del progetto LARA e a quella dell'applicazione del metodo Feuerstein.

No abstract