Development of a special purpose spacecraft interior coating. Phase 2

Numerous acrylic and epoxy modifiers for the fluorocarbon latex resin base were investigated. Optimum coatings were developed by modifying the fluorocarbon latex with an epoxy acrylic resin system. In addition, a number of other formulations, containing hard acrylics as modifiers, displayed attractive properties and potential for further improvements. The preferred formulations dried to touch in about one hour and were fully dried in about twenty four hours under normal room temperature and humidity conditions. In addition to physical and mechanical properties either comparable or superior to those of commercial solvent base polyurethane or polyester coatings, the preferred compositions meet the flammability and offgassing requirements specified by NASA

Sensitive methods for estimating the anchoring strength of nematic liquid crystals on Langmuir-Blodgett monolayers of fatty acids

The anchoring of the nematic liquid crystal N-(p-methoxybenzylidene)-p-butylaniline (MBBA) on Langmuir-Blodgett monolayers of fatty acids (COOHC$_{n}$H$_{2n+1}$) was studied as a function of the length of the fatty acid alkyl chains, $n$ ($n = 15, 17, 19, 21$). The monolayers were deposited onto ITO-coated glass plates which were used to assemble sandwich cells of various thickness that were filled with MBBA in the nematic phase. The mechanism of relaxation from the flow-induced quasi-planar to the surface-induced homeotropic alignment was studied for the four decreases linearly with increasing the length of the alkyl chains $n$ which suggests that the Langmuir-Blodgett film plays a role in the phenomenon. This fact was confirmed by a sensitive estimation of the anchoring strength of MBBA on the fatty acid monolayers after anchoring breaking which takes place at the transition between two electric-field--induced turbulent states, denoted as DSM1 and DSM2. It was found that the threshold electric field for the anchoring breaking, which can be considered as a measure of the anchoring strength, also decreases linearly as $n$ increases. Both methods thus possess a high sensitivity in resolving small differences in anchoring strength. In cells coated with mixed Langmuir-Blodgett monolayers of two fatty acids ($n=15$ and $n=17$) a maximum of the relaxation speed was observed when the two acids were present in equal amount. This observation homeotropic cells by changing the ratio between the components of the surfactant film.Comment: LaTeX article, 20 pages, 15 figures, 17 EPS files. 1 figure added, references moved. Submitted to Phys. Rev.

“TECAR® : terapia complementare nelle disfunzioni dell’atm” .

LaTECAR®(terapiaaTrasferimentoEnergeticoCapacitivoeResistivo),introdottainItaliadaalcunianni,è una apparecchiaturasempre piùdiffusanellariabilitazionedilesioniosteoartic olariemuscolarisiaacutechecroniche.Lasuautilitàèriconosciutaecertificatadadiversistudi1-5:abbreviaitempidirecuperoriabilitativoeriduceildolore6,7;stimolaenergiadall’internodeitessuti,attraversol’incrementodellatemperaturainternaelariattivazionedellacircolazione,stimolandoinaturaliprocessiriparativieantinfiammatori8-11. LaTecar®sfruttaunaformadiinterazioneelettromagnetica,chefariferimentoalmodellofisicodelcondensatore,conuncontattocapacitivoe/oresistivo9-,10. Nellaterapiadelledisfunzionidelsistemacranio-cervico-mandibolarealcuniprocessipatologici, intraedextraarticolari,risultanoparticolarmenteresistentialtrattamentoconfarmaci,biteefisioterapiamanuale. L’obiettivo di questo studio è quellodiillustrareilsistemaTECAR®,iprincipidifunzionamentoelecaratteristichegiàconosciutenellariabilitazionedeitraumimuscolotendinei12-15edipresentareunaprimavalutazioneclinicadelsuoutilizzocometerapiacomplementareperilrecuperodialcuniquadridelledisfunzioniacutecronichedell’ATM.Taleterapiaèd’appoggioallaterapiaglobaleodontoiatricagnatologica(bite)efisioterapica(terapiamanuale)

Is cholecystectomy a risk factor in the development of gastric neoplasms?]

Some studies suggest cholecystectomy and the cholelithiasic disease are frequently associated to some neoplasms of the digestive tract. Cholecystectomy, through the physiopathologic alterations it causes, seems to assume the role of factor of risk for the development of a gastric neoplasm. The authors reviewed their casuistry by analysing the percentages of subjects in whom the gastric neoplasm was associated to a previous cholecystectomy or a concomitant cholelithiasis. The data obtained do not support the hypothesis that cholecystectomy or the "lithogenicity of the biliary ducts" may be a factor of risk for gastric cancer

Poliedri: non solo geometria.

Le attività descritte si propongono di avvicinare gli studenti a un tema, la geometria dello spazio, che è poco sviluppato nella programmazione didattica, nonostante il carattere “concreto” che sembra vantare a confronto di altri settori della matematica. Si evidenzia l'opportunità offerta dalla tematica per attivare utili collegamenti interdisciplinari a differenti livelli di profondità. Si espongono i contenuti principali presi a riferimento nella progettazione e nello svolgimento del laboratorio, si descrivono alcuni aspetti rilevanti della loro implementazione didattica, si descrivono gli esiti che sono parsi maggiormente significativi. Si conclude con alcune note sulla modalità adottata nella collaborazione con gli insegnanti delle classi del Liceo Scientifico “N. Copernico” in cui si è svolta l’esperienza di laboratorio, nell'ambito del progetto "Lauree scientifiche" sviluppato a Pavia

Expression, microsomal and mitochondrial activities of cytochrome P450 enzymes in brain regions from control and phenobarbital-treated rabbits

Expression and monooxygenase activity of various cytochrome P450 (CYP) enzymes along with constitutive androstane (CAR) and the pregnane X (PXR) receptors were investigated in the brain of control and phenobarbital-treated rabbits (80 mg/kg for 4 days). RT-PCR analysis, using specific primers, demonstrated that in control rabbits mRNAs of CYP 2A10, 2B4/5 and 3A6 were expressed, though to a different extent, in the liver, as well as in brain cortex, midbrain, cerebellum, striatum, hippocampus and hypothalamus, whilst CYP2A11 and 4B1 were not expressed in the hypothalamus. CAR was expressed in liver and all the brain regions examined, whereas the PXR was expressed only in liver and cortex. Real time RT-PCR analysis demonstrated that in vivo treatment with phenobarbital, in contrast with what happened in liver, did not induce the expression of CYP 2B4/5 mRNA in cortex, midbrain and cerebellum. NADPH cytochrome c reductase and some other enzymatic activities markers of CYP 2A, 2B, 3A and 4B activities were studied in liver microsomes as well as in microsomes and mitochondria of brain cortex, midbrain and cerebellum of control and phenobarbital-treated rabbits. In contrast to what was observed in liver, phenobarbital treatment did not induce the aforementioned monooxygenase activities in brain. However, we cannot exclude that a longer phenobarbital treatment may lead to a significant induction of CYP activities in brain. These findings indicated that brain CYPs, despite the presence of CAR, were resistant to phenobarbital induction, indicating a possible different regulation of these enzymes between brain and liver