Literatur

Analytical and Bioanalytical Chemistry -     

New applications of the thermodilatometry in the characterization of ceramics

Thermodilatometry is widely used at high temperatures for studying ceramics. The sintering process can be monitored but if the rate of shrinkage is too high, it may produce a structure damage, therefore an adapted software is available to work at a constant sintering rate.Structural changes can be studied as well as the expansion of ceramic fibres.

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Zusammenfassung Zur Untersuchung von keramischen Substanzen bei hohen Temperaturen ist Thermodilatometrie ein weitverbreitete Methode. Der Sinterproze\ kann verfolgt werden, ist jedoch die Schrumpfgeschwindigkeit zu hoch, kann es zu Strukturschäden kommen, deshalb ist eine angeglichene Software erhältlich, die das Arbeiten bei konstanter Sintergeschwindigkeit ermöglicht.Es können sowohl die strukturellen Veränderungen als auch die Ausdehnung von Keramikfasern untersucht werden.

     

Synthesis of 1-hydroxy-2H,5H-dihydroisoxazolo[5,4-c]quinoline. A novel heterocyclic ring system

The synthesis of a new heterocyclic compound, 3a , combining a quinoline and a isoxazolol ring is described. The preparation involves cyclisation of the carbamate 14 , followed by concomitant deprotection of the acidic and amino functions to give compound 3a , the stable tautomeric form of 3 .     

Experiments on 40 Gb/s Transmission with Wavelength Conversion: Results from the IST ATLAS Project

In this article we report the main experimental results obtained in the framework of the IST ATLAS project regarding the transmission at 40 Gb/s over long terrestrial links, including the frequency conversion of a signal. We report the single-channel 40 Gb/s transmission over a link 500 km long with an amplifier spacing of 100 km, both with G.652 fibers and G.653 fibers by periodically compensating the chromatic dispersion with dispersion-compensating fibers. We report the single-channel transmission at 40 Gb/s, also, after the wavelength conversion of a channel with both PPLN and semiconductor optical amplifier devices. In particular, 500 km distances are obtained with PPLN wavelength conversion and 300 km distances with semiconductor optical amplifiers. Some results have been reported for electronic devices operating at 40 Gb/s.     

Synthesis, characterization, and application of indolo[3,2-b]carbazole semiconductors

The synthesis, characterization, and field-effect transistor (FET) properties of new indolo[3,2-b]carbazoles are described. In particular, an extensive characterization of their crystal structures has revealed the importance of the nature of the side chains (alkyl, phenyl, thienyl substituents) on their solid-state organization. These organic materials have exhibited p-type FET behavior with hole mobilities as high as 0.2 cm2 V(-1) s(-1) with an on/off current ratio higher than 10(6). Best results were obtained with phenyl-substituted indolo[3,2-b]carbazoles since the presence of phenyl substituents seems to allow efficient overlap between the oligomeric molecules. More importantly, FET properties were kept constant during several months in air.     

Addition of difluoromethyl radicals to glycals: a new route to alpha-CF2-D-glycosides

The synthesis of synthetically useful alpha-CF2-glycosides by radical addition of ethyl bromodifluoroacetate onto 2-benzyloxyglycals is described. The methodology provides an access to alpha-O-glycoside mimics and, potentially, to valuable alpha-O-glycoconjugate analogues.     

Synthesis of bridgehead-substituted azabicyclo[2.2.1]heptane and -[3.3.1]nonane derivatives for the elaboration of α7 nicotinic ligands

Azabicyclo[2.2.1]heptane and -[3.3.1]nonane scaffolds (X = Cl, Br) containing a pyridinyl substituent at the bridgehead position were prepared via two complementary chemical pathways, either by the transformation of a methoxy group into a synthetically valuable chlorine atom at the C-6 position of the pyridine moiety or by means of a regioselective C-6 deprotonation/halogenation process of the pyridine moiety exemplified by chlorination or bromination. These newly generated scaffolds were then engaged in Suzuki-Miyaura coupling reactions to provide α7 nicotinic ligands. Both chemical series were evaluated in vitro for their affinity at α7 nicotinic receptors, revealing nanomolar potency with significant selectivity over the α4β2 nicotinic subtype. These approaches offer a general access to these α7 nicotinic scaffolds and ligands.     

Improvements of the electrochemical features of graphite fluorides in primary lithium battery by electrodeposition of polypyrrole

Improvements of the electrochemical features of CF_x cathode materials in primary lithium battery were obtained by the electrodeposition of polypyrrole (PPy) performed in acetonitrile with Py monomer. The electrodeposition does not affect the core of the CF_x powder as revealed by XRD and TEM. The maximum discharge rate which is 1C for pristine CF_x increases for PPy–CF_x and reaches 4C in the case of PPy–CF_0.80 1 M LiPF₆–EC:DMC (1:1) electrolyte. A maximum power density of 5235 W/kg (4C-rate) has been achieved with PPy–CF_0.80, a value around 3.8 times higher than for CF_0.80 (1C-rate).